Java For Loop Explained – Syntax, For-Each, Examples & Best Practices

Introduction – Repetition Made Easy

Suppose you want to print numbers 1 through 10 — doing this manually is inefficient and error-prone. That’s where the Java for loop helps.
It’s one of the most powerful tools for controlled iteration in Java.

In this article, you’ll learn:

• How the basic and enhanced for loop works
• When to use for, while, or do...while
• Real-world examples with arrays and collections
• Loop control using break and continue

What is a for Loop in Java?

A for loop lets you execute a block of code a fixed number of times, using a loop counter.

Basic Syntax of Java For Loop

for (initialization; condition; update) {
    // code block to be executed
}

Explanation:

• Initialization: Start a counter (e.g., int i = 0)
• Condition: Runs while true
• Update: Executes after each loop (e.g., i++)

Example: Print Numbers 1 to 5

for (int i = 1; i <= 5; i++) {
    System.out.println("i = " + i);
}

Explanation:

• i = 1 → loop starts at 1
• i <= 5 → condition
• i++ → increments by 1 each time

Reverse Looping Example

for (int i = 5; i >= 1; i--) {
    System.out.println("Countdown: " + i);
}

Explanation:

• Decreases i from 5 to 1
• Useful for reverse iterations or countdowns

Enhanced For Loop (for-each)

Introduced in Java 5, enhanced for loop is used to iterate through arrays or collections.

String[] fruits = {"Apple", "Banana", "Cherry"};

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

Explanation:

• String fruit → local variable
• : fruits → the array being looped
• Cleaner and safer for read-only traversal

You cannot modify array elements directly in an enhanced for loop.

For Loop with Arrays

int[] nums = {10, 20, 30};

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

Explanation:

• Loops from index 0 to nums.length - 1
• Accesses and prints each array element

Using break and continue in For Loops

for (int i = 1; i <= 5; i++) {
    if (i == 3) continue;  // skip when i is 3
    if (i == 5) break;     // stop when i is 5
    System.out.println(i);
}

Output: 1, 2, 4
Explanation:

• continue skips the current iteration
• break exits the loop early

For Loop vs While Loop – Quick Comparison

Best Practices for Java For Loop

Tips:

• Use for when number of iterations is known
• Prefer enhanced for for readability when not modifying array
• Don’t forget i++ — or you’ll end up in an infinite loop!

Avoid off-by-one errors:

for (int i = 0; i <= arr.length; i++)  //  causes ArrayIndexOutOfBounds

Summary

Java for loops are ideal for repeated actions with a known number of steps.
Whether you’re working with indexes, arrays, or collections, for provides clean and effective control.

Key Takeaways:

• Master both basic and enhanced for loops
• Apply break and continue for finer control
• Use enhanced for when reading from arrays or lists

FAQs – Java For Loop

What is the difference between for and enhanced for loop?

The enhanced for (for-each) loop simplifies iterating over arrays and collections, but it’s not suitable for modifying elements.

Can I use break and continue in a for loop?

Yes! break exits the loop, and continue skips to the next iteration.

When should I use a for loop over a while loop?

Use a for loop when you know how many times you need to iterate.

Can we use multiple variables in a for loop?

Yes, you can initialize and update multiple variables:

for (int i = 0, j = 10; i < j; i++, j--) { }

Does Java have a foreach loop?

Yes! The enhanced for loop is Java’s version of foreach.