Cornelius Eanes's Programming Portal
Assignments (Methods)
[90] Picture Menu
GOAL: Learn how to call methods
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: Picture Menu
/// File Name: PictureMenu.java
/// Date Finished: Feb 19, 2016
import java.util.Scanner;
public class PictureMenu
{
public static void main( String[] args )
{
Scanner kb = new Scanner(System.in);
int choice;
System.out.println( "1. Butterfly " );
System.out.println( "2. Elephant " );
System.out.println( "3. Teddy Bear" );
System.out.println( "4. Snake " );
System.out.print( "\nWhich animal to draw? " );
choice = kb.nextInt();
System.out.println();
if ( choice == 1 )
{
butterfly();
butterfly();
// the method is ran twice, rather, the code in that method is ran twice
}
else if ( choice == 2 )
{
elephant();
}
else if ( choice == 3 )
{
teddybear();
}
else if ( choice == 4 )
{
snake();
}
else
{
System.out.println( "Sorry, that wasn't one of the choices." );
}
System.out.println( "\nGoodbye!" );
}
public static void butterfly()
{
System.out.println(" .==-. .-==. ");
System.out.println(" \\()8`-._ `. .' _.-'8()/ ");
System.out.println(" (88\" ::. \\./ .:: \"88) ");
System.out.println(" \\_.'`-::::.(#).::::-'`._/ ");
System.out.println(" `._... .q(_)p. ..._.' ");
System.out.println(" \"\"-..-'|=|`-..-\"\" ");
System.out.println(" .\"\"' .'|=|`. `\"\". ");
System.out.println(" ,':8(o)./|=|\\.(o)8:`. ");
System.out.println(" (O :8 ::/ \\_/ \\:: 8: O) ");
System.out.println(" \\O `::/ \\::' O/ ");
System.out.println(" \"\"--' `--\"\" hjw");
}
public static void elephant()
{
System.out.println(" _..--\"\"-. .-\"\"--.._ ");
System.out.println(" _.-' \\ __...----...__ / '-._");
System.out.println(" .' .:::...,' ',...:::. '.");
System.out.println("( .'``'''::; ;::'''``'. )");
System.out.println(" \\ '-) (-' /");
System.out.println(" \\ / \\ /");
System.out.println(" \\ .'.-. .-.'. /");
System.out.println(" \\ | \\0| |0/ | /");
System.out.println(" | \\ | .-==-. | / |");
System.out.println(" \\ `/`; ;`\\` /");
System.out.println(" '.._ (_ | .-==-. | _) _..'");
System.out.println(" `\"`\"-`/ `/' '\\` \\`-\"`\"`");
System.out.println(" / /`; .==. ;`\\ \\");
System.out.println(" .---./_/ \\ .==. / \\ \\");
System.out.println(" / '. `-.__) | `\"");
System.out.println(" | =(`-. '==. ;");
System.out.println(" jgs \\ '. `-. /");
System.out.println(" \\_:_) `\"--.....-'");
}
public static void teddybear()
{
System.out.println(" ___ .--. ");
System.out.println(" .--.-\" \"-' .- |");
System.out.println(" / .-,` .'");
System.out.println(" \\ ` \\");
System.out.println(" '. ! \\");
System.out.println(" | ! .--. |");
System.out.println(" \\ '--' /.____");
System.out.println(" /`-. \\__,'.' `\\");
System.out.println(" __/ \\`-.____.-' `\\ /");
System.out.println(" | `---`'-'._/-` \\----' _");
System.out.println(" |,-'` / | _.-' `\\");
System.out.println(" .' / |--'` / |");
System.out.println(" / /\\ ` | |");
System.out.println(" | .\\/ \\ .--. __ \\ |");
System.out.println(" '-' '._ / `\\ /");
System.out.println(" jgs `\\ ' |------'`");
System.out.println(" \\ | |");
System.out.println(" \\ /");
System.out.println(" '._ _.'");
System.out.println(" ``");
}
public static void snake()
{
System.out.println(" ,,'6''-,.");
System.out.println(" <====,.;;--.");
System.out.println(" _`---===. \"\"\"==__");
System.out.println(" //\"\"@@-\\===\\@@@@ \"\"\\\\");
System.out.println(" |( @@@ |===| @@@ ||");
System.out.println(" \\\\ @@ |===| @@ //");
System.out.println(" \\\\ @@ |===|@@@ //");
System.out.println(" \\\\ |===| //");
System.out.println("___________\\\\|===| //_____,----\"\"\"\"\"\"\"\"\"\"-----,_");
System.out.println(" \"\"\"\"---,__`\\===`/ _________,---------,____ `,");
System.out.println(" |==|| `\\ \\");
System.out.println(" |==| | pb ) |");
System.out.println(" |==| | _____ ______,--' '");
System.out.println(" |=| `----\"\"\" `\"\"\"\"\"\"\"\" _,-'");
System.out.println(" `=\\ __,---\"\"\"-------------\"\"\"''");
System.out.println(" \"\"\"\" ");
}
}
Output
[91] Flicker Phase
GOAL: Learn what methods do.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: PROGRAM_NAME
/// File Name: FlickerPhrase.java
/// Date Finished: Feb 19, 2016
import java.util.Random;
public class FlickerPhrase
{
public static void main( String[] args ) throws Exception
{
Random rng = new Random();
int r;
for ( int i=0; i<100000; i++ )
{
r = 1 + rng.nextInt(5) + 1;
// Write five if statements here.
// If r is 1, then call the method named 'first'.
// If r is 2, then call the method named 'second', and so on.
if (r == 1) {
first();
} else if (r == 2) {
second();
} else if (r == 3) {
third();
} else if (r == 4) {
fourth();
} else if (r == 5) {
fifth();
}
//Thread.sleep(1000);
// Optional: after the if statements are over, add in a slight delay.
}
System.out.println("I pledge allegiance to the flag.");
}
public static void first()
{
System.out.print("I \r");
}
public static void second()
{
System.out.print(" pledge \r");
}
public static void third()
{
System.out.print(" allegiance \r");
}
public static void fourth()
{
System.out.print(" to the \r");
}
public static void fifth()
{
System.out.print(" flag.\r");
}
}
Output
[92] Heron's Formula
GOAL: Use a method that has a return value.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: Heron's Formula
/// File Name: HeronsForumula.java
/// Date Finished: Feb 19, 2016
public class HeronsFormula
{
public static void main( String[] args )
{
double a;
a = triangleArea(3, 3, 3);
System.out.println("A triangle with sides 3,3,3 has an area of " + a );
a = triangleArea(3, 4, 5);
System.out.println("A triangle with sides 3,4,5 has an area of " + a );
a = triangleArea(7, 8, 9);
System.out.println("A triangle with sides 7,8,9 has an area of " + a );
System.out.println("A triangle with sides 5,12,13 has an area of " + triangleArea(5, 12, 13) );
System.out.println("A triangle with sides 10,9,11 has an area of " + triangleArea(10, 9, 11) );
System.out.println("A triangle with sides 8,15,17 has an area of " + triangleArea(8, 15, 17) );
System.out.println("A triangle with sides 9,9,9 has an area of " + triangleArea(9, 9, 9));
}
public static double triangleArea( int a, int b, int c )
{
// the code in this method computes the area of a triangle whose sides have lengths a, b, and c
double s, A;
s = (a+b+c) / 2.0;
A = Math.sqrt( s*(s-a)*(s-b)*(s-c) );
return A;
// ^ after computing the area, "return" it
}
/*
* Both code snippets return the same results.
* The class with the extra method is 23 lines long (with whitespace and comments removed).
* The class without the extra method is 44 lines long (with whitespace and comments removed).
* It was easier to fix the file with the method, as I only had to change one value.
* It was easier to add to the class with the method, as I only needed one line of code.
*/
}
Output
[93] Distance Formula
GOAL: Use a method to easily calculate the distance formula.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: Distance Formula
/// File Name: DistanceFormula.java
/// Date Finished: Feb 19, 2016
public class DistanceFormula
{
public static void main( String[] args )
{
// test the formula a bit
double d1 = distance(-2,1 , 1,5);
System.out.println(" (-2,1) to (1,5) => " + d1 );
double d2 = distance(-2,-3 , -4,4);
System.out.println(" (-2,-3) to (-4,4) => " + d2 );
System.out.println(" (2,-3) to (-1,-2) => " + distance(2,-3,-1,-2) );
System.out.println(" (4,5) to (4,5) => " + distance(4,5,4,5) );
}
public static double distance( int x1, int y1, int x2, int y2 )
{
return Math.sqrt((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1));
}
}
Output
[94] Month Name
GOAL: Using a method, figure out what month it is.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: PROGRAM_NAME
/// File Name: MonthName.java
/// Date Finished: Feb 19, 2016
public class MonthName
{
public static String monthName( int month )
{
String result;
// Your code goes in here.
if (month == 1) {
result = "January";
} else if (month == 2) {
result = "February";
} else if (month == 3) {
result = "March";
} else if (month == 4) {
result = "April";
} else if (month == 5) {
result = "May";
} else if (month == 6) {
result = "June";
} else if (month == 7) {
result = "July";
} else if (month == 8) {
result = "August";
} else if (month == 9) {
result = "September";
} else if (month == 10) {
result = "October";
} else if (month == 11) {
result = "November";
} else if (month == 12) {
result = "December";
} else {
result = "error";
}
return result;
}
public static void main( String[] args )
{
System.out.println( "Month 1: " + monthName(1) );
System.out.println( "Month 2: " + monthName(2) );
System.out.println( "Month 3: " + monthName(3) );
System.out.println( "Month 4: " + monthName(4) );
System.out.println( "Month 5: " + monthName(5) );
System.out.println( "Month 6: " + monthName(6) );
System.out.println( "Month 7: " + monthName(7) );
System.out.println( "Month 8: " + monthName(8) );
System.out.println( "Month 9: " + monthName(9) );
System.out.println( "Month 10: " + monthName(10) );
System.out.println( "Month 11: " + monthName(11) );
System.out.println( "Month 12: " + monthName(12) );
System.out.println( "Month 43: " + monthName(43) );
}
}
Output
[95] Month Offset
GOAL: Using a method, figure out a month's offset when calculating the weekday.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: PROGRAM_NAME
/// File Name: MonthOffset.java
/// Date Finished: Feb 19, 2016
public class MonthOffset
{
public static int monthOffset( int m )
{
int result;
// Your code goes in here.
if (m == 1) {
result = 1;
} else if (m == 2) {
result = 4;
} else if (m == 3) {
result = 4;
} else if (m == 4) {
result = 0;
} else if (m == 5) {
result = 2;
} else if (m == 6) {
result = 5;
} else if (m == 7) {
result = 0;
} else if (m == 8) {
result = 3;
} else if (m == 9) {
result = 6;
} else if (m == 10) {
result = 1;
} else if (m == 11) {
result = 4;
} else if (m == 12) {
result = 6;
} else {
result = -1;
}
return result;
}
public static void main( String[] args )
{
System.out.println( "Offset for month 1: " + monthOffset(1) );
System.out.println( "Offset for month 2: " + monthOffset(2) );
System.out.println( "Offset for month 3: " + monthOffset(3) );
System.out.println( "Offset for month 4: " + monthOffset(4) );
System.out.println( "Offset for month 5: " + monthOffset(5) );
System.out.println( "Offset for month 6: " + monthOffset(6) );
System.out.println( "Offset for month 7: " + monthOffset(7) );
System.out.println( "Offset for month 8: " + monthOffset(8) );
System.out.println( "Offset for month 9: " + monthOffset(9) );
System.out.println( "Offset for month 10: " + monthOffset(10) );
System.out.println( "Offset for month 11: " + monthOffset(11) );
System.out.println( "Offset for month 12: " + monthOffset(12) );
System.out.println( "Offset for month 43: " + monthOffset(43) );
}
}
Output
[96] Weekday Calculator
GOAL: Using previous methods, calculate what weekday you were born on.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: Weekday Calculator
/// File Name: WeekdayCalculator.java
/// Date Finished: Feb 25, 2016
import java.util.Scanner;
public class WeekdayCalculator {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("What's your birthday? (MM DD YYYY)");
System.out.print("> ");
int month = input.nextInt();
int day = input.nextInt();
int year = input.nextInt();
String result = getWeekdayString(day, month, year);
System.out.println("You were born on " + result + "!");
}
public static int getMonthOffset(int m) {
int result;
if (m == 1) {
result = 1;
} else if (m == 2) {
result = 4;
} else if (m == 3) {
result = 4;
} else if (m == 4) {
result = 0;
} else if (m == 5) {
result = 2;
} else if (m == 6) {
result = 5;
} else if (m == 7) {
result = 0;
} else if (m == 8) {
result = 3;
} else if (m == 9) {
result = 6;
} else if (m == 10) {
result = 1;
} else if (m == 11) {
result = 4;
} else if (m == 12) {
result = 6;
} else {
result = -1;
}
return result;
}
public static boolean isLeapYear(int year) {
return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
}
public static String getWeekdayName(int weekday) {
String result;
if (weekday == 1) {
result = "Sunday";
} else if (weekday == 2) {
result = "Monday";
} else if (weekday == 3) {
result = "Tuesday";
} else if (weekday == 4) {
result = "Wednesday";
} else if (weekday == 5) {
result = "Thursday";
} else if (weekday == 6) {
result = "Friday";
} else if (weekday == 7) {
result = "Saturday";
} else {
result = "error";
}
return result;
}
public static String getMonthName(int month) {
String result;
if (month == 1) {
result = "January";
} else if (month == 2) {
result = "February";
} else if (month == 3) {
result = "March";
} else if (month == 4) {
result = "April";
} else if (month == 5) {
result = "May";
} else if (month == 6) {
result = "June";
} else if (month == 7) {
result = "July";
} else if (month == 8) {
result = "August";
} else if (month == 9) {
result = "September";
} else if (month == 10) {
result = "October";
} else if (month == 11) {
result = "November";
} else if (month == 12) {
result = "December";
} else {
result = "error";
}
return result;
}
public static String getWeekdayString(int day, int month, int year) {
int yy = year - 1900;
int total = yy / 4;
total += yy;
total += day;
total += getMonthOffset(month);
if (isLeapYear(year) || month == 1 || month == 2) {
total--;
}
int r = total % 7;
String weekdayStr = getWeekdayName(r);
String monthStr = getMonthName(month);
return weekdayStr + ", " + monthStr + " " + day + ", " + year;
}
}
Output
[97] Area Calculator
GOAL: Calculate the areas of shapes with methods.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: Area Calculator
/// File Name: AreaCalculator.java
/// Date Finished: Feb 25, 2016
import java.util.Scanner;
public class AreaCalculator {
public static double getAreaCircle(double radius) {
return Math.PI * (radius * radius);
}
public static double getAreaRectangle(double length, double width) {
return length * width;
}
public static double getAreaTriangle(double base, double height) {
return 0.5 * base * height;
}
public static double getAreaSquare(double length) {
return length * length;
}
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Shape Area Calculator\n");
int choice = -1;
while (choice != 5) {
System.out.println("1) Square\n2) Rectangle\n3) Triangle\n4) Circle\n5) Quit");
System.out.print("> ");
choice = input.nextInt();
System.out.println();
if (choice == 1) {
System.out.print("Length: ");
double length = input.nextDouble();
System.out.println("\nThe area is " + getAreaSquare(length) + ".\n");
} else if (choice == 2) {
System.out.print("Length: ");
double length = input.nextDouble();
System.out.print("Width: ");
double width = input.nextDouble();
System.out.println("\nThe area is " + getAreaRectangle(length, width) + ".\n");
} else if (choice == 3) {
System.out.print("Base: ");
double base = input.nextDouble();
System.out.print("Height: ");
double height = input.nextDouble();
System.out.println("\nThe area is " + getAreaTriangle(base, height) + ".\n");
} else if (choice == 4) {
System.out.print("Radius: ");
double radius = input.nextDouble();
System.out.println("\nThe area is " + getAreaCircle(radius) + ".\n");
}
}
}
}
Output
[98] Function Call Alphabet
GOAL: Correctly print a lot of stuff to the screen.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: Function Call Alphabet
/// File Name: MethodCallAlphabet.java
/// Date Finished: Feb 26, 2016
// Method Call Alphabet - Yet another program to practice methods, but this time it's method calls only.
public class MethodCallAlphabet
{
public static void main( String[] args )
{
// ???? a( ???? ); // displays a word beginning with A
// ???? b( ???? ); // returns the word to be displayed
// ???? c( ???? ); // pass it 'true' and it will display a word beginning with C
// ???? d( ???? ); // displays a word beginning with D
// ???? e( ???? ); // pass it the number of letters to display (9)
// ???? f( ???? ); // displays the word you pass it beginning with "F"
// ???? g( ???? ); // returns the word to be displayed
// ???? h( ???? ); // tell it how many times to display the word (1)
a();
System.out.print(b());
c(true);
d();
e(9);
f("Frog");
System.out.print(g());
h(1);
// ???? i( ???? ); // pass it any integer and it will display a word beginning with I
// ???? j( ???? ); // returns a different word depending on what you pass it (1-3)
// ???? k( ???? ); // displays a word beginning with K
// ???? l( ???? ); // displays a different word depending on the two booleans you pass it
// ???? m( ???? ); // displays a different word depending on the two booleans you pass it
// ???? n( ???? ); // displays the word you pass it beginning with "N"
// ???? o( ???? ); // displays a word beginning with O and returns a useless value
// ???? p( ???? ); // returns the word to be displayed
// ???? q( ???? ); // displays the word
System.out.println();
i(Integer.MAX_VALUE);
j(1);
j(2);
j(3);
k();
l(true, true);
l(true, false);
m(true, false);
m(false, false);
n("Noodles");
o();
System.out.print(p());
q();
// ???? r( ???? ); // returns a different word depending on if you pass it 'true' or 'false'
// ???? s( ???? ); // pass it the number of letters to display (6)
// ???? t( ???? ); // displays the word you pass it beginning with "T"
// ???? u( ???? ); // returns the word to be displayed
// ???? v( ???? ); // tell it how many times to display the word (1)
// ???? w( ???? ); // pass it any integer and it will display a word beginning with W
// ???? x( ???? ); // returns a different word depending on what you pass it (1-2)
// ???? y( ???? ); // displays a word beginning with Y
// ???? z( ???? ); // returns a different word depending on which two boolean values you pass it
System.out.println();
r(true);
r(false);
s(6);
t("Tough");
System.out.print(u());
v(1);
w(0xff000000);
x(1);
x(2);
y();
z(true, true);
z(false, false);
System.out.println();
}
/**************************************
* Don't change anything below here!! *
*************************************/
// More code down here...
Output
[99] Fill-In Functions
GOAL: Fix the code so it compiles and works.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: Fill-In Functions
/// File Name: FillInMethods.java
/// Date Finished: Feb 26, 2016
// Fill-In Methods - Fix the broken methods and method calls.
public class FillInMethods
{
public static void main( String[] args )
{
// Fill in the method calls where appropriate.
System.out.println("Watch as we demonstrate methods.");
System.out.println();
System.out.println("I'm going to get a random character from A-Z");
char c;
c = randChar();
System.out.println("The character is: " + c );
System.out.println();
System.out.println("Now let's count from -10 to 10");
int begin, end;
begin = -10;
end = 10;
counter(begin, end);
System.out.println("How was that?");
System.out.println();
System.out.println("Now we take the absolute value of a number.");
int x, y;
x = -10;
y = abso(x);
System.out.println("|" + x + "| = " + y );
System.out.println();
System.out.println("That's all. This program has been brought to you by:");
credits();
}
public static void credits()
// No parameters.
{
// displays some boilerplate text saying who wrote this program, etc.
System.out.println();
System.out.println("programmed by Graham Mitchell");
System.out.println("modified by Cornelius Eanes");
System.out.print("This code is distributed under the terms of the standard ");
System.out.println("BSD license. Do with it as you wish.");
}
public static char randChar()
// No parameters.
{
// chooses a random character in the range "A" to "Z"
int numval;
char charval;
// pick a random number from 0 to 25
numval = (int)(Math.random()*26);
// now add that offset to the value of the letter 'A'
charval = (char) ('A' + numval);
return charval;
}
public static int counter(int start, int stop)
// Parameters are:
// int start;
// int stop;
{
// counts from start to stop by ones
int ctr;
ctr = start;
while ( ctr <= stop )
{
System.out.print(ctr + " ");
ctr = ctr+1;
}
return ctr;
}
public static int abso(int value)
// Parameters are:
// int value;
{
// finds the absolute value of the parameter
int absval;
if ( value < 0 )
absval = -value;
else
absval = value;
return absval;
}
}
Output
[100] More Fill-In Methods
GOAL: Fix some more code so it compiles and runs.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: More Fill-In Methods
/// File Name: MoreFillInMethods.java
/// Date Finished: Feb 26, 2016
// More Fill-In Methods - Fix the broken methods and method calls (again).
import java.util.Scanner;
public class MoreFillInMethods
{
public static void main( String[] args )
{
// Fill in the method calls where indicated.
System.out.println("Here we go.");
System.out.println();
System.out.println("Some random numbers, if you please: ");
int lo, hi, val1, val2;
lo = 1;
hi = 10;
val1 = superRand(lo, hi);
System.out.println("First: " + val1 );
val2 = superRand(hi, lo); // this time, put hi first
System.out.println("Second: " + val2 );
if ( val1 == val2 )
System.out.println("Hey! They were the same!");
else
System.out.println("They were not the same.");
System.out.println();
System.out.print("More counting, but this time not by ones: ");
// count from 2 to 8 by 2s
stepCount(2, 8, 2);
// count from 10 to 2 by 2s
stepCount(10, 2, 2);
System.out.println();
System.out.println("Let's figure a project grade.");
int a = 4, b = 3, c = 4, d = 5, e = 2, f = 1, result;
result = projectGrade(a, b, c, d, e, f);
System.out.println("434521 -> " + result );
System.out.println();
System.out.print("Finally, some easy ones.");
String namae;
namae = getName();
System.out.println("Hi, " + namae );
System.out.println();
System.out.println("Do you feel lucky, punk?");
crash();
System.out.println();
}
public static int superRand(int a, int b)
// Parameters are:
// int a;
// int b;
{
// picks a number between a and b, no matter which is larger
int c;
if ( a < b ) // b is larger
c = a + (int)(Math.random()*(b-a+1));
else if ( a > b ) // a is larger
c = b + (int)(Math.random()*(a-b+1));
else
c = a; // or c = b; doesn't matter since they're equal
return c;
}
public static int stepCount(int first, int last, int step)
// Parameters are:
// int first;
// int last;
// int step;
{
// counts from 'first' to 'last' by 'step'
// handles forward and backward
int x;
if ( first < last )
{
x = first;
while ( x <= last )
{
System.out.print(x + " ");
x = x + step;
}
}
else
{
x = first;
while ( x >= last )
{
System.out.print(x + " ");
x = x - step;
}
}
return x;
}
public static int projectGrade(int p1, int p2, int p3, int p4, int p5, int p6)
// Parameters are:
// int p1, p2, p3, p4, p5, p6;
{
// given six integers representing scores out of five in each of the
// six categories for the first six weeks project: tells you your
// overall project grade out of 100
int overall_grade;
overall_grade = p1 * 6; // six points per point for the first category
overall_grade = overall_grade + ( p2 * 6 ); // six points per point
overall_grade = overall_grade + ( p3 * 4 ); // four points per point
overall_grade = overall_grade + ( p4 * 2 ); // two points per point
overall_grade = overall_grade + ( p5 * 1 ); // one point per point
overall_grade = overall_grade + ( p6 * 1 ); // one point per point
return overall_grade;
}
public static String getName()
// No parameters.
{
// finds out the user's name
Scanner keyboard = new Scanner(System.in);
String name;
System.out.print("Please enter your name: ");
name = keyboard.next();
return name;
}
public static String crash()
// No parameters.
{
// displays "you win" or "you lose". You lose 90% of the time.
String magic_word;
if ( (int)(Math.random()*10) == 0 )
{
// What do you know? We won!
magic_word = "win";
}
else
{
// No big suprise; we lost.
magic_word = "lose";
}
System.out.print("you " + magic_word);
return magic_word;
}
}
Output
[101] Keychains for Sale
GOAL: Write a skeleton of a keychain-buying program.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: Keychains for Sale
/// File Name: KeychainsForSale.java
/// Date Finished: Feb 26, 2016
import java.util.Scanner;
public class KeychainsForSale {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
boolean run = true;
System.out.println("Ye Olde Keychains Shoppe");
System.out.println();
while (run) {
System.out.println("1. Add keychains to order");
System.out.println("2. Remove keychains from order");
System.out.println("3. View current order");
System.out.println("4. Checkout");
System.out.println();
System.out.print("> ");
int choice = input.nextInt();
if (choice == 1) {
addKeychains();
} else if (choice == 2) {
removeKeychains();
} else if (choice == 3) {
viewOrder();
} else if (choice == 4) {
checkout();
run = false;
}
}
}
public static void addKeychains() {
System.out.println("// TODO: Add keychains");
}
public static void removeKeychains() {
System.out.println("// TODO: Remove keychains");
}
public static void viewOrder() {
System.out.println("// TODO: View order");
}
public static void checkout() {
System.out.println("// TODO: Checkout order");
}
}
Output
[102] Keychains for Sale, for real this time
GOAL: Complete the keychain assignment.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: Keychains for Sale, For Real This Time
/// File Name: KeychainsForSale2.java
/// Date Finished: Feb 26, 2016
import java.util.Scanner;
public class KeychainsForSale2 {
private static Scanner input;
private static int keychainCount;
private static double cost;
public static void main(String[] args) {
input = new Scanner(System.in);
keychainCount = 0;
cost = 10.00;
boolean run = true;
System.out.println("Ye Olde Keychains Shoppe");
System.out.println();
while (run) {
System.out.println("1. Add keychains to order");
System.out.println("2. Remove keychains from order");
System.out.println("3. View current order");
System.out.println("4. Checkout");
System.out.println();
System.out.print("> ");
int choice = input.nextInt();
System.out.println();
if (choice == 1) {
addKeychains();
} else if (choice == 2) {
removeKeychains();
} else if (choice == 3) {
viewOrder();
} else if (choice == 4) {
checkout();
run = false;
}
System.out.println();
}
}
public static void addKeychains() {
System.out.println("You have " + keychainCount + " keychain(s).");
System.out.println("How many keychains do you want to add?");
System.out.print("> ");
int amount = input.nextInt();
keychainCount += amount;
System.out.println("You now have " + keychainCount + " keychain(s).");
}
public static void removeKeychains() {
System.out.println("You have " + keychainCount + " keychain(s).");
System.out.println("How many keychains do you want to remove?");
System.out.print("> ");
int amount = input.nextInt();
keychainCount -= amount;
System.out.println("You now have " + keychainCount + " keychain(s).");
}
public static void viewOrder() {
System.out.println("Number of keychains: " + keychainCount);
System.out.println("Cost per keychain: $" + zeroPad(cost));
System.out.println("Total: $" + zeroPad(calculateTotal()));
}
public static void checkout() {
System.out.print("Please enter your name: ");
String name = input.next();
viewOrder();
System.out.println("Thanks for your order, " + name + "!");
}
public static String zeroPad(double d) {
return String.format("%01.02f", d);
}
public static double calculateTotal() {
return cost * keychainCount;
}
}
Output
[103] Keychains for Sale, real ultimate power
GOAL: Modify the completed keychain assignment to include sales tax and shipping fees and error checking.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: Keychains for Sale: Ultimate Power
/// File Name: KeychainsForSale3.java
/// Date Finished: Feb 29, 2016
import java.util.Scanner;
public class KeychainsForSale3 {
private static Scanner input;
private static int keychainCount;
private static double cost, tax, shippingInitial, shippingMarginal;
public static void main(String[] args) {
input = new Scanner(System.in);
keychainCount = 0;
cost = 10.00;
tax = 0.0825;
shippingInitial = 5.00;
shippingMarginal = 1.00;
boolean run = true;
System.out.println("Ye Olde Keychains Shoppe");
System.out.println();
while (run) {
System.out.println("1. Add keychains to order");
System.out.println("2. Remove keychains from order");
System.out.println("3. View current order");
System.out.println("4. Checkout");
System.out.println();
System.out.print("> ");
int choice = input.nextInt();
System.out.println();
if (choice == 1) {
addKeychains();
} else if (choice == 2) {
removeKeychains();
} else if (choice == 3) {
viewOrder();
} else if (choice == 4) {
checkout();
run = false;
}
System.out.println();
}
}
public static void addKeychains() {
boolean next = false;
int amount = -1;
while (!next) {
System.out.println("You have " + keychainCount + " keychain(s).");
System.out.println("How many keychains do you want to add?");
System.out.print("> ");
amount = input.nextInt();
if (!checkKeychains(amount)) {
System.out.println("ERROR: Cannot have a negative keychain count.\n");
} else {
next = true;
}
}
keychainCount += amount;
System.out.println("You now have " + keychainCount + " keychain(s).");
}
public static void removeKeychains() {
boolean next = false;
int amount = -1;
while (!next) {
System.out.println("You have " + keychainCount + " keychain(s).");
System.out.println("How many keychains do you want to remove?");
System.out.print("> ");
amount = input.nextInt();
if (!checkKeychains(-amount)) {
System.out.println("ERROR: Cannot have a negative keychain count.\n");
} else {
next = true;
}
}
keychainCount -= amount;
System.out.println("You now have " + keychainCount + " keychain(s).");
}
public static void viewOrder() {
System.out.println("Number of keychains: " + keychainCount);
System.out.println("Cost per keychain: $" + zeroPad(cost));
System.out.println("Shipping charges ($" + zeroPad(shippingInitial) + " + $" + zeroPad(shippingMarginal) +
" for each keychain): $" + zeroPad(calculateShippingCharges()));
System.out.println("Subtotal: $" + zeroPad(calculateSubtotal()));
System.out.println("Tax Charge (" + String.format("%01.02f", tax * 100) + "%): $" + zeroPad(calculateTaxCharge()));
System.out.println("Total: $" + zeroPad(calculateTotal()));
}
public static void checkout() {
System.out.print("Please enter your name: ");
String name = input.next();
viewOrder();
System.out.println("Thanks for your order, " + name + "!");
}
public static double calculateShippingCharges() {
return shippingInitial + shippingMarginal * keychainCount;
}
public static double calculateSubtotal() {
return keychainCount * cost + calculateShippingCharges();
}
public static double calculateTotal() {
return calculateSubtotal() * (1.0 + tax);
}
public static double calculateTaxCharge() {
return calculateSubtotal() * tax;
}
public static String zeroPad(double d) {
return String.format("%01.02f", d);
}
public static boolean checkKeychains(int amount) {
return keychainCount + amount >= 0;
}
}
Output
[104] Calling Methods from Other Files
GOAL: Learn how to call methods from other files.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: Calling Methods from Other Files
/// File Name: MethodsFromOtherFiles.java
/// Date Finished: Feb 29, 2016
// Don't worry about the package naming
import ifstatements._36.WeekdayName;
import methods._94.MonthName;
import methods._95.MonthOffset;
import methods._96.WeekdayCalculator;
import java.util.Scanner;
public class MethodsFromOtherFiles {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("What's your birthday? (MM DD YYYY)");
System.out.print("> ");
int month = input.nextInt();
int day = input.nextInt();
int year = input.nextInt();
String result = getWeekdayString(day, month, year);
System.out.println("You were born on " + result + "!");
}
public static String getWeekdayString(int day, int month, int year) {
int yy = year - 1900;
int total = yy / 4;
total += yy;
total += day;
total += MonthOffset.monthOffset(month);
if (WeekdayCalculator.isLeapYear(year) || month == 1 || month == 2) {
total--;
}
int r = total % 7;
String weekdayStr = WeekdayName.getWeekdayName(r);
String monthStr = MonthName.monthName(month);
return weekdayStr + ", " + monthStr + " " + day + ", " + year;
}
}
Output
[105] Evenness Method
GOAL: Using methods, figure out what numbers are even or divisible by 3.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: Evenness Method
/// File Name: Evenness.java
/// Date Finished: Feb 29, 2016
public class Evenness {
public static boolean isEven(int i) {
return i % 2 == 0;
}
public static boolean isDivisibleBy3(int i) {
return i % 3 == 0;
}
public static void main(String[] args) {
for (int i = 1; i <= 20; i++) {
System.out.print(i + " ");
if (isEven(i)) {
System.out.print("<");
}
if (isDivisibleBy3(i)) {
System.out.print("=");
}
System.out.println();
}
}
}
Output
[106] Finding Prime Numbers
GOAL: Using a method, find as many prime numbers as possible.
/// Name: Cornelius Eanes
/// Period: 5
/// Program Name: Finding Prime Numbers
/// File Name: PrimeNumbers.java
/// Date Finished: Feb 29, 2016
public class PrimeNumbers {
public static boolean isPrime(int n) {
for (int i = n - 1; i > 1; i--) {
if (n % i == 0) {
return false;
}
}
return true;
}
public static void main(String[] args) {
for (int i = 2; i <= 100; i++) {
if (isPrime(i)) {
System.out.println(i);
}
}
}
}
Output
