The for loop is one of the most commonly used looping constructs in Java. It allows you to repeat a block of code a specific number of times, making it ideal for tasks like processing elements in a sequence, repeating actions with a known count, or generating patterns. You will often use a for loop when you know in advance how many times you want to execute a statement or a block of statements.

A for loop in Java consists of three main parts: initialization, condition, and increment. The general structure looks like this:

for (initialization; condition; increment) {
    // Code to execute in each iteration
}

• Initialization: this step is executed once, before the loop starts. It is typically used to declare and set up a loop control variable, such as int i = 1;
• Condition: before each iteration, the condition is checked. If it evaluates to true, the loop body executes. If it is false, the loop stops. For example, i <= 5 keeps the loop running as long as i is less than or equal to 5;
• Increment: after each iteration of the loop body, the increment statement runs. It usually updates the loop control variable, such as i++ to increase i by 1.

Putting these together, the for loop in the example starts by setting i to 1, checks if i is less than or equal to 5, prints the value, and then increases i by 1. This process repeats until the condition is no longer true.

Example

Imagine you want to print numbers from 1 to 5 in Java. Instead of writing System.out.println(1), System.out.println(2), and so on, you can use a for loop to do it automatically.

This Java program prints numbers from 1 to 5 using a for loop. The loop starts at 1, checks the condition i <= 5, and increments i by 1 after each iteration, printing each number in the console.