For Each Loop

A school program needs reliable data and clear rules. An enhanced for loop visits each element of an array or iterable. It is useful when a marks report needs each value without its position.

When you're working with arrays or collections in Java, there comes a point where you just want to go through every element—no counters, no fuss. That's where the for-each loop shines. It's Java's way of saying: "Let me handle the iteration, you focus on what needs to be done."

The for-each loop—also known as the enhanced for loop—is a control flow statement introduced in Java 5. It’s designed to iterate over elements in arrays and collections without the need for an index variable.

for (datatype element : collection) {
    // use element
}

Here’s what each part means:

• datatype: the type of the elements (e.g., int, String)
• element: a temporary variable representing the current item in the loop
• collection: an array or iterable collection

public class ForEachArrayExample {
    public static void main(String[] args) {
        int[] numbers = {10, 20, 30, 40, 50};

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

Value: 10
Value: 20
Value: 30
Value: 40
Value: 50

Here’s a side-by-side thought:

• With a traditional loop: you control every step of iteration.
• With a for-each loop: Java handles the loop mechanics for you.

It’s clean, readable, and removes the risk of off-by-one errors.

public class ForEachString {
    public static void main(String[] args) {
        String[] fruits = {"Apple", "Banana", "Cherry"};

        for (String fruit : fruits) {
            System.out.println("Fruit: " + fruit);
        }
    }
}

Fruit: Apple
Fruit: Banana
Fruit: Cherry

import java.util.ArrayList;

public class ForEachCollection {
    public static void main(String[] args) {
        ArrayList<String> colors = new ArrayList<>();
        colors.add("Red");
        colors.add("Green");
        colors.add("Blue");

        for (String color : colors) {
            System.out.println("Color: " + color);
        }
    }
}

Color: Red
Color: Green
Color: Blue

Good question—and here's a warning. You can’t change the original array or collection items directly inside a for-each loop, at least not for primitives or immutable objects.

int[] values = {1, 2, 3};
for (int value : values) {
    value = value * 2; // This doesn't change the array!
}

// values remain {1, 2, 3}

Why? Because value is a copy of each item, not a direct reference.

public class ForEach2DArray {
    public static void main(String[] args) {
        int[][] matrix = {
            {1, 2},
            {3, 4},
            {5, 6}
        };

        for (int[] row : matrix) {
            for (int val : row) {
                System.out.print(val + " ");
            }
            System.out.println();
        }
    }
}

1 2
3 4
5 6

While for-each makes code cleaner, it does come with limitations:

• You can’t get the index of the current element.
• You can’t remove items from a collection safely (unless using an Iterator).
• Direct element modification (like updating an array value) is not possible for primitive arrays.

Use it when:

• You need to access every element one by one
• You don’t care about the index
• Your code needs to be clean, readable, and minimal

The for-each loop is your go-to tool for readable, streamlined iteration. It removes distractions so you can focus on what matters: processing data. Whether you're looping over fruit names, colors, or 2D matrices, for-each keeps your intent clear and your code crisp.

Assigning to the loop variable does not replace a primitive element in the array. Use an indexed loop when positions or replacement are needed.

Before running this Java program, write down each line you expect to see. Identify the value, branch, object or exception responsible for each line. Then explain whether the following assumption is valid: Assigning to the loop variable does not replace a primitive element in the array.

Java 17 · Main.java · complete practice program

public class Main  {
  public static void main(String[] args)  {
    int[] marks =  {
      70, 80
    }
    ;
    for (int mark : marks)  {
      System.out.println(mark);
    }
  }
}

Now change one thing: Add 90 to the marks array. Predict the new behavior before checking the worked variation.

Java 17 · Main.java · source repeated for this answer

public class Main  {
  public static void main(String[] args)  {
    int[] marks =  {
      70, 80
    }
    ;
    for (int mark : marks)  {
      System.out.println(mark);
    }
  }
}

Expected output

70
80

An enhanced for loop visits each element of an array or iterable. It is useful when a marks report needs each value without its position.

Assigning to the loop variable does not replace a primitive element in the array. Use an indexed loop when positions or replacement are needed.

Run with javac Main.java, then java Main. The declaration of Main names the class; main starts the example, and println writes a complete output line.

Worked variation: Add 90 to the marks array. The enhanced for loop visits it after 70 and 80.

An enhanced for loop visits each element of an array or iterable. It is useful when a marks report needs each value without its position. Assigning to the loop variable does not replace a primitive element in the array. Use an indexed loop when positions or replacement are needed.

Related explanations: Java Variables, Java If Statement - Syntax and Examples, Java Class - Blueprint of Objects, Exceptions in Java Introduction.

Supporting documentation: Official Java learning guide and Java 17 language specification.