Introduction

The for loop in Java is a control flow statement that allows code to be executed repeatedly based on a condition. It is commonly used when the number of iterations is known beforehand.

Syntax of the For Loop

for (initialization; condition; increment/decrement) {
  // Code to be executed
}
      

Key Points:

• The initialization step is executed once at the start of the loop.
• The condition is evaluated before each iteration. If it evaluates to false, the loop terminates.
• The increment/decrement step is executed at the end of each iteration.
• A for loop can be used with arrays, lists, and other collections.

Examples of the For Loop

1. Basic Example

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

Output:

Value of i: 1
Value of i: 2
Value of i: 3
Value of i: 4
Value of i: 5
      

2. Using a For Loop with an Array

int[] numbers = {10, 20, 30, 40, 50};
for (int i = 0; i < numbers.length; i++) {
  System.out.println("Element at index " + i + ": " + numbers[i]);
}
      

Output:

Element at index 0: 10
Element at index 1: 20
Element at index 2: 30
Element at index 3: 40
Element at index 4: 50
      

3. Enhanced For Loop (For-Each)

int[] numbers = {10, 20, 30, 40, 50};
for (int num : numbers) {
  System.out.println("Number: " + num);
}
      

Output:

Number: 10
Number: 20
Number: 30
Number: 40
Number: 50
      

4. Nested For Loop

for (int i = 1; i <= 3; i++) {
  for (int j = 1; j <= 3; j++) {
    System.out.print("(" + i + ", " + j + ") ");
  }
  System.out.println();
}
      

Output:

(1, 1) (1, 2) (1, 3) 
(2, 1) (2, 2) (2, 3) 
(3, 1) (3, 2) (3, 3)
      

Unsolved Problems