Java For Loop
Syntax, Flow & Examples

Java For Loop

The for loop in Java is used to repeat a block of code a certain number of times. It's concise, predictable, and incredibly useful when you know in advance how many times a loop should run.

Syntax of a Java For Loop

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

This syntax has three parts:

• Initialization: Executed once before the loop starts.
• Condition: Checked before each iteration. Loop continues if this is true.
• Update: Executed after each iteration. Usually increments or decrements a variable.

Basic Example: Print 1 to 5

public class ForLoopExample {
    public static void main(String[] args) {
        for (int i = 1; i <= 5; i++) {
            System.out.println("Number: " + i);
        }
    }
}

Number: 1
Number: 2
Number: 3
Number: 4
Number: 5

Explanation: The loop starts with i = 1. As long as i <= 5, the loop executes and prints the current value. After every iteration, i++ increases i by 1.

Descending For Loop

for (int i = 5; i > 0; i--) {
    System.out.println(i);
}

5
4
3
2
1

Here, we reverse the iteration by starting at 5 and decreasing i until it becomes less than or equal to 0.

Loop with Custom Step Size

for (int i = 0; i <= 10; i += 2) {
    System.out.println("Even: " + i);
}

Even: 0
Even: 2
Even: 4
Even: 6
Even: 8
Even: 10

Instead of incrementing by 1, here we increment by 2 to skip even numbers directly.

Looping Over an Array

One of the most common use cases for a for loop is iterating over arrays:

String[] fruits = { "Apple", "Banana", "Mango" };
for (int i = 0; i < fruits.length; i++) {
    System.out.println(fruits[i]);
}

Apple
Banana
Mango

Infinite For Loop

A for loop without a condition can result in an infinite loop:

for (;;) {
    System.out.println("This goes on forever...");
}

This loop runs endlessly since there's no condition to stop it. Use such loops carefully, often in conjunction with a break statement.

Using Break to Exit a For Loop

for (int i = 1; i <= 10; i++) {
    if (i == 6) break;
    System.out.println(i);
}

1
2
3
4
5

Once i == 6, the loop exits. The break statement is often used to terminate loops early based on a condition.

Using Continue to Skip an Iteration

for (int i = 1; i <= 5; i++) {
    if (i == 3) continue;
    System.out.println(i);
}

1
2
4
5

When i == 3, the continue statement skips that iteration and continues with the next one.

Real-Life Analogy

Imagine checking your emails every morning for the next 7 days. A for loop is like automating this task: "Start on Monday, repeat daily, and stop after Sunday." Simple, predictable, effective — just like a for loop!

Practice Ideas

• Print all odd numbers from 1 to 100
• Find the sum of the first 10 natural numbers
• Print a pattern like a triangle using nested for loops