Lesson 2 of 516 minModule progress 0%

Module 7: Arrays and ArrayList

Looping Through Arrays

Use `for` and enhanced `for` loops to process every value in an array without repetitive code.

Author

Java Learner Editorial Team

Reviewer

Technical review by Java Learner

Last reviewed

2026-04-16

Java version

Java 25 LTS

How this lesson was prepared: AI-assisted draft, edited by hand, and checked against current Java 25 documentation and runnable examples.

Learning goals

  • Loop through arrays with a regular `for` loop
  • Use the enhanced `for-each` loop for simple reads
  • Choose the loop style that matches the task

Arrays are often used together with loops: Once you have several values, looping becomes the natural way to process them all.

A regular for loop is useful when you need the index: It helps when you want positions, replacement, or side-by-side calculations.

The enhanced for-each loop is useful when you only need each value: It reads cleanly for simple printing or summing tasks.

Pick the simpler loop when possible: Use indexes only when the problem really needs them.

Runnable examples

Regular `for` loop with indexes

public class Main {
    public static void main(String[] args) {
        String[] names = {"Ada", "Grace", "Linus"};

        for (int i = 0; i < names.length; i++) {
            System.out.println(i + ": " + names[i]);
        }
    }
}

Expected output

0: Ada
1: Grace
2: Linus

Enhanced `for-each` loop

public class Main {
    public static void main(String[] args) {
        int[] numbers = {2, 4, 6};

        for (int number : numbers) {
            System.out.println(number);
        }
    }
}

Expected output

2
4
6

Mini exercise

Print every score in an array using a `for-each` loop.

Summary

  • Use `for` when you need indexes.
  • Use `for-each` when you only need values.
  • Loops turn grouped data into practical work.

Next step

Now apply loops to common array tasks such as totals, maximum values, and searching.

Sources used

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Lesson check

When is a regular `for` loop usually better than `for-each`?

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