For Loop

A for loop is a type of loop used when the number of repetitions is known in advance.
It is commonly used for:

counting
iterating over a range of values
repeating an action a fixed number of times

The Three Main Parts of a For Loop

A for loop usually consists of three key parts:

Initial condition Sets the starting point of the loop.
Termination condition Determines when the loop should stop.
Increment / Decrement Updates the loop variable after each iteration.

Conceptual Flow

start → check condition → run action → update → repeat

As long as the condition is true, the loop continues.

Example 1: Python (Printing Hello World)

for i in range(3):
    print("Hello, World")

Explanation:

The loop runs 3 times
"Hello, World" is printed on each iteration
No need to repeat the print statement manually

Example 2: JavaScript

for (let i = 0; i < 3; i++) {
    console.log("Hello, World");
}

Explanation:

let i = 0 → initial condition
i < 3 → termination condition
i++ → increment

The logic is identical to Python, only the syntax differs.

Example 3: C Language

for (int i = 0; i < 3; i++) {
    printf("Hello, World\n");
}

Explanation:

int i = 0 → starting value
i < 3 → loop condition
i++ → increment after each iteration

Key Takeaway from the Examples

Although Python, JavaScript, and C look different:

they all use an initial value
they all check a condition
they all update the loop variable
they all repeat an action automatically

The concept of a for loop is universal, even if the syntax changes.

When to Use a For Loop

Use a for loop when:

the number of repetitions is known
you are iterating over a range or sequence
repetition follows a clear pattern

If repetition depends on a condition that may change unpredictably, use a while loop instead.

Summary

A for loop repeats code a fixed number of times
It consists of initial condition, termination condition, and increment/decrement
The same idea applies across different programming languages
Syntax may differ, but the logic stays the same