For Loop in Java - Syntax, Examples & Best Practices

Introduction

The for loop is one of the most commonly used loops in Java. It's perfect when you know how many times you want to repeat a block of code.

Basic Syntax

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

Simple Examples

Print Numbers 1 to 10

public class ForLoopExample {
    public static void main(String[] args) {
        for (int i = 1; i <= 10; i++) {
            System.out.println(i);
        }
    }
}

Sum of First N Numbers

public class SumExample {
    public static void main(String[] args) {
        int n = 100;
        int sum = 0;
        
        for (int i = 1; i <= n; i++) {
            sum += i;
        }
        
        System.out.println("Sum of 1 to " + n + " = " + sum);
    }
}

Iterate Over Array

public class ArrayLoop {
    public static void main(String[] args) {
        int[] numbers = {10, 20, 30, 40, 50};
        
        for (int i = 0; i < numbers.length; i++) {
            System.out.println("Element at index " + i + ": " + numbers[i]);
        }
    }
}

Enhanced For Loop (For-Each)

Java provides an enhanced for loop for iterating over arrays and collections:

public class ForEachExample {
    public static void main(String[] args) {
        String[] fruits = {"Apple", "Banana", "Orange", "Mango"};
        
        for (String fruit : fruits) {
            System.out.println(fruit);
        }
    }
}

Nested For Loops

public class MultiplicationTable {
    public static void main(String[] args) {
        for (int i = 1; i <= 10; i++) {
            for (int j = 1; j <= 10; j++) {
                System.out.print(i * j + "\t");
            }
            System.out.println();
        }
    }
}

Summary

• For loops repeat code a specific number of times
• Use enhanced for loop for arrays and collections
• Nested loops are useful for 2D operations
• Always ensure the loop will eventually terminate