Iteration with 2D Array
Focus is on iteration. This example uses 2D array with simple ASCII art. .
/*
* Creator: Nighthawk Coding Society
* Mini Lab Name: Hello Series,featuring Monkey Jumpers
*/
/**
* Class for Monkeys: a 2D array of Monkeys
* As well as method to print the Poem
*/
class MonkeyLoop {
//The area between class definition and the 1st method is where we keep data for object in Java
String [][] monkeys; //2D Array: AP CSA Unit 8: 2D array of strings
//2D array is like a grid [x][y]
// or like a spreadsheet [row][column]
/**
* Constructor initializes a 2D array of Monkeys
*/
public MonkeyLoop() {
//Storing Data in 2D arrays
monkeys = new String[][]{ //2D array above is just a name, "new" makes a container ("object")
//Monkey 0
{
"ʕง ͠° ͟ل͜ ͡°)ʔ ", //[0][0] eyes
" \\_⏄_/ ", //[0][1] chin
" --0-- ", //[0][2] body
" ⎛ ⎞ " //[0][3] legs
},
//Monkey 1
{
" ʕ༼ ◕_◕ ༽ʔ", //[1][0]
" \\_⎏_/ ",
" ++1++ ",
" ⌋ ⌊ "
},
//Monkey 2
{
" ʕ(▀ ⍡ ▀)ʔ", //[2][0]
" \\_⎐_/ ",
" <-2-> ",
" 〈 〉 "
},
//Monkey 3
{
"ʕ ͡° ͜ʖ ° ͡ʔ", //[3][0]
" \\_⍾_/ ",
" ==3== ",
" _/ \\_ "
},
//Monkey 4
{
" (◕‿◕✿) ", //[4][0]
" \\_∀_/ ", //[4][1]
" ==5== ", //[4][2]
" _/ \\_ " //[4][3]
},
//Monkey 5
{
" ʕ•ᴥ•ʔ ", //[4][0]
" \\_⍾_/ ", //[4][1]
" ==4== ", //[4][2]
" _/ \\_ " //[4][3]
}
};
}
/**
* Loop and print monkeys in array
* ... repeat until you reach zero ...
*/
public void printPoem() {
//begin the poem
System.out.println();
System.out.println("Monkey Jumpers Poem in Java Loopy");
// monkeys (non-primitive) defined in constructor knows its length
int monkeyCount = monkeys.length;
for (int i = monkeyCount; i >= 1; i--) //loops through 2D array length backwards
{
//this print statement shows current count of Monkeys
// concatenation (+) of the loop variable and string to form a countdown message
System.out.println(i + " little monkeys jumping on the bed...");
//how many separate parts are there in a monkey monkey?
for (int row = 0; row < monkeyCount; row++) { //cycles through "cells" of 2d array
/*cycles through columns to print
each monkey part by part, will eventually print entire column*/
for (int col = 0; col < monkeys[row].length; col++) {
// prints specific part of the monkey from the column
System.out.print(monkeys[row][col] + " ");
//this is new line between separate parts
System.out.println();
}
//this new line gives separation between stanza of poem
System.out.println();
}
//countdown for poem, decrementing monkeyCount variable by 1
monkeyCount -= 1;
}
//out of all the loops, prints finishing messages
System.out.println("No more monkeys jumping on the bed");
System.out.println("0000000000000000000000000000000000");
System.out.println(" THE END ");
}
public void printPoemHorizontal() {
System.out.println();
System.out.println("Monkey Jumpers Poem Horizontal in Java Loopy");
int monkeyCount = monkeys.length;
int row = 0;
for (int i = monkeyCount; i >= 1; i--) {
System.out.println(i + " little monkeys jumping on the bed...");
for (int col = 0; col < monkeys[0].length; col++) {
for (row = 0; row < monkeyCount; row++) {
System.out.print(monkeys[row][col] + " ");
}
System.out.println();
}
System.out.println();
monkeyCount -= 1;
}
System.out.println("No more monkeys jumping on the bed");
System.out.println("0000000000000000000000000000000000");
System.out.println(" THE END ");
}
/**
* A Java Driver/Test method that is the entry point for execution
*/
public static void main(String[] args) {
new MonkeyLoop().printPoemHorizontal(); //a new monkey list and output in one step
}
}
MonkeyLoop.main(null);
This code swaps out the rows and columns in the for loops, therefore printing all elements in the same row first (the head, then the body, etc). So, it prints the monkeys horizontally.
import java.util.ArrayList;
/*
* Creator: Nighthawk Coding Society
* Mini Lab Name: Hello Series,featuring Monkey Jumpers
*/
/**
* Class for Monkey: a 2D array of Monkey
* As well as method to print the Poem
*/
class Monkey {
//The area between class definition and the 1st method is where we keep data for object in Java
private static ArrayList<String[]> monkeyList = new ArrayList<String[]>(); //2D Array: AP CSA Unit 8: 2D array of strings
private String[] monkeyASCII;
/**
* Constructor initializes a 2D array of Monkey
*/
public Monkey(String[] monkeyASCII) {
this.monkeyASCII = monkeyASCII;
monkeyList.add(monkeyASCII);
}
/**
* Loop and print monkey in array
* ... repeat until you reach zero ...
*/
public static void printPoem() {
//begin the poem
System.out.println();
System.out.println("Monkey Jumpers Poem in Java with Objects!!!");
// monkey (non-primitive) defined in constructor knows its length
int monkeyCount = monkeyList.size();
for (int i = 1; i <= monkeyCount; i++) //loops through 2D array length forwards
{
//this print statement shows current count of Monkey
// concatenation (+) of the loop variable and string to form a countdown message
System.out.println(i + " little monkey jumping on the bed...");
//how many separate parts are there in a monkey monkey?
for (int row = 0; row < i; row++) { //cycles through "cells" of 2d array
/*cycles through columns to print
each monkey part by part, will eventually print entire column*/
for (int col = 0; col < monkeyList.get(row).length; col++) {
// prints specific part of the monkey from the column
System.out.print(monkeyList.get(row)[col] + " ");
//this is new line between separate parts
System.out.println();
}
//this new line gives separation between stanza of poem
System.out.println();
}
//countdown for poem, decrementing monkeyCount variable by 1
monkeyCount -= 1;
}
//out of all the loops, prints finishing messages
System.out.println("Too many monkeys jumping on the bed");
System.out.println("0000000000000000000000000000000000");
System.out.println(" THE END ");
}
/**
* A Java Driver/Test method that is the entry point for execution
*/
public static void main(String[] args) {
Monkey monkey0 = new Monkey(new String[]{
"ʕง ͠° ͟ل͜ ͡°)ʔ ", //[0][0] eyes
" \\_⏄_/ ", //[0][1] chin
" --0-- ", //[0][2] body
" ⎛ ⎞ " //[0][3] legs
});
Monkey monkey1 = new Monkey(new String[]{
" ʕ༼ ◕_◕ ༽ʔ", //[1][0]
" \\_⎏_/ ",
" ++1++ ",
" ⌋ ⌊ "
});
Monkey monkey2 = new Monkey(new String[]{
" ʕ(▀ ⍡ ▀)ʔ", //[2][0]
" \\_⎐_/ ",
" <-2-> ",
" 〈 〉 "
});
Monkey monkey3 = new Monkey(new String[]{
"ʕ ͡° ͜ʖ ° ͡ʔ", //[3][0]
" \\_⍾_/ ",
" ==3== ",
" _/ \\_ "
});
Monkey monkey4 = new Monkey(new String[]{
" (◕‿◕✿) ", //[4][0]
" \\_⍾_/ ", //[4][1]
" ==4== ", //[4][2]
" _/ \\_ " //[4][3]
});
Monkey.printPoem(); //a new monkey list and output in one step
}
}
Monkey.main(null);
This code creates a constructor for a monkey, taking in a string array input to take as the ascii art and adding it to a 2D array. The print poem similarly iterates through this ArrayList like before, printing the monkeys as expected. This is more scalable as you can add more and more monkeys.
I also printed them backwards by swapping the conditions in the for loops, starting from monkeycount instead of 0.
Hacks (Mini-lab)
Build you own Jupyter Notebook. Feel free to use any ASCII art of your choice, there are some much better ones here. My little guys were made up out of my head while looking at unicode characters.
- Print monkeys horizontally versus vertically.
- Build more or entire rhyme for the "Monkey Jumpers" countdown poem
- Add names or other properties to the monkeys
In you notebook, illustrate or answer some of these questions.
- Is this program in more of an Imperative Programming Style or OOP style? Explain.
- Observe variable assignments.
- Is each Monkey an object?
- Build an where the monkey is an object versus two-dimensional array. This would be leading into Unit 5 requirements.
- Study loops and zero based counting
- Study two-dimensional (2D) array references
- Explain different way you can access a 2D array