for Loop

In Java, the for loop is used to repeatedly execute a block of code a certain number of times. It provides a concise and structured way to iterate over a range of values or elements in an array or collection. The basic syntax of the for loop is as follows:

for (initialization; condition; update) {
    // Code to be executed in each iteration
}

Initialization: Executes once before the loop starts. It is used to initialize the loop control variable.
Condition: Checked before each iteration. If it evaluates to true, the loop continues; otherwise, the loop exits.
Update: Executed after each iteration. It is used to update the loop control variable.

Example:

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

In this example:

• int i = 1 initializes the loop control variable i to 1.
• i <= 5 is the condition. As long as this condition is true, the loop continues.
• i++ is the update statement. It increments the value of i after each iteration.

The output of this program will be:

1
2
3
4
5

Enhanced for Loop (for-each):

In addition to the traditional for loop, Java provides an enhanced for loop, also known as the for-each loop. It simplifies the iteration over elements in an array or collection. The syntax is as follows:

for (element_type element_variable : array_or_collection) {
    // Code to be executed for each element
}

Example using an array:

public class EnhancedForLoopExample {
    public static void main(String[] args) {
        int[] numbers = {1, 2, 3, 4, 5};

        for (int num : numbers) {
            System.out.println(num);
        }
    }
}

In this example, num takes on the value of each element in the numbers array in each iteration of the loop.

Nested for Loops:

You can also have nested for loops, where one for loop is inside another. This is often used for iterating over two-dimensional arrays or for performing nested iterations.

for (int i = 1; i <= 3; i++) {
    for (int j = 1; j <= 2; j++) {
        System.out.println("i: " + i + ", j: " + j);
    }
}

This nested loop will produce the following output:

i: 1, j: 1
i: 1, j: 2
i: 2, j: 1
i: 2, j: 2
i: 3, j: 1
i: 3, j: 2

The outer loop runs three times, and for each iteration of the outer loop, the inner loop runs twice.

The for loop is a fundamental construct for repetitive tasks in Java, and mastering its usage is essential for writing efficient and readable code.