Loops

Java while Loop

The while statement in Java repeatedly runs code as long as the given condition remains true. 

int count = 0;
while (count < 5) {
    System.out.println("Count is: " + count);
    count++;
}

For Loop in Java

The for loop repeats code over a range of values by initializing a variable, checking a condition, and updating the variable each iteration. 

public class LoopExample {
    public static void main(String[] args) {
        for (int i = 0; i < 5; i++) {
            System.out.println("Iteration " + i);
        }
    }
}
/*
Iteration 0
Iteration 1
Iteration 2
Iteration 3
Iteration 4
*/

For-each statement in Java

In Java, the for-each statement allows you to directly loop through each item in an array or ArrayList and perform some action with each item.

When creating a for-each statement, you must include the for keyword and two expressions inside of parentheses, separated by a colon. These include:

  1. The handle for an element we’re currently iterating over.

  2. The source array or ArrayList we’re iterating over.

// array of numbers
int[] numbers = {1, 2, 3, 4, 5};


// for-each loop that prints each number in numbers
// int num is the handle while numbers is the source array
for (int num : numbers) {  
	System.out.println(num);
}
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