For loop Syntax

For loop is a control flow statement in programming that allows you to execute a block of code repeatedly based on a specified condition. It is commonly used when you know how many times you want to execute a block of code.

For loop Syntax

The syntax of For loop varies slightly depending on the programming language, but the basic structure is similar across many languages.

for (initialization; condition; update) {
    // Code block to be executed repeatedly as long as the condition is true
}

Here’s a general overview of the Syntax of For loop:

1. Initialization: This is where you initialize the loop control variable. This variable is typically used to keep track of the current iteration of the loop.
2. Condition: This is the condition that is evaluated before each iteration of the loop. If the condition is true, the loop continues; otherwise, it terminates.
3. Update: This is where you update the loop control variable. Typically, you increment or decrement the variable to ensure progress toward the loop termination condition.

For loop Syntax in C/C++:

Syntax:

for (initialization; condition; update) {
    // Code block to be executed repeatedly as long as the condition is true
}

Explanation of the Syntax:

• In C and C++, the for loop is initialized with an initial condition, followed by a loop condition, and an increment or decrement operation.
• The loop first executes the initialization part, typically used to initialize loop control variables.
• It then evaluates the condition specified in the loop header.
• If the condition is true, the code block within the curly braces {} is executed.
• After executing the code block, the loop performs the increment or decrement operation.
• The loop then returns to the loop header and re-evaluates the condition. If the condition remains true, the process continues; otherwise, the loop terminates.

Implementation of For loop Syntax in C/C++:

C++

#include <iostream>
using namespace std;

int main()
{
    // For loop
    for (int i = 0; i < 10; i++) {
        cout << i << " ";
    }

    return 0;
}

C

#include <stdio.h>

int main()
{
    // For loop
    for (int i = 0; i < 10; i++) {
        printf("%d ", i);
    }

    return 0;
}

Output

0 1 2 3 4 5 6 7 8 9 

For loop Syntax in Java:

Syntax:

for (initialization; condition; update) {
    // Code block to be executed repeatedly as long as the condition is true
}

Explanation of the Syntax:

• In Java, the for loop operates similarly to C and C++.
• It begins with an initialization expression, followed by a loop condition, and an increment or decrement operation.
• The loop first executes the initialization part.
• It then evaluates the condition specified in the loop header.
• If the condition is true, the code block within the curly braces {} is executed.
• After executing the code block, the loop performs the increment or decrement operation.
• The loop returns to the loop header and re-evaluates the condition. If the condition remains true, the process continues; otherwise, the loop terminates.

Implementation of For loop Syntax in Java:

Java

/*package whatever //do not write package name here */

import java.io.*;

class GFG
{
    public static void main(String[] args)
    {
        // For loop
        for (int i = 0; i < 10; i++) {
            System.out.print(i + " ");
        }
    }
}

Output

0 1 2 3 4 5 6 7 8 9 

For loop Syntax Python:

Syntax:

for variable in iterable:
    # Code block to be executed repeatedly for each element in the iterable

Explanation of the Syntax:

• Python’s for loop iterates over the elements of an iterable object, such as lists, tuples, strings, etc.
• It assigns each element of the iterable to the specified variable and executes the code block for each element.
• The loop continues until all elements of the iterable have been processed.

Implementation of For loop Syntax in Python:

Python3

# For loop
for i in range(10):
    print(i, end=" ")

Output

0 1 2 3 4 5 6 7 8 9 

For loop Syntax in C#:

Syntax:

for (initialization; condition; update) {
    // Code block to be executed repeatedly as long as the condition is true
}

Explanation of the Syntax:

• In C#, the for loop behaves similarly to C, C++, and Java.
• It starts with an initialization expression, followed by a loop condition, and an increment or decrement operation.
• The loop first executes the initialization part.
• It then evaluates the condition specified in the loop header.
• If the condition is true, the code block within the curly braces {} is executed.
• After executing the code block, the loop performs the increment or decrement operation.
• The loop returns to the loop header and re-evaluates the condition. If the condition remains true, the process continues; otherwise, the loop terminates.

Implementation of For loop Syntax in C#:

C#

using System;

public class GFG {

    static public void Main()
    {
        // For loop
        for (int i = 0; i < 10; i++) {
            Console.Write(i + " ");
        }
    }
}

Output

0 1 2 3 4 5 6 7 8 9 

JavaScript (JS) For loop Syntax:

Syntax:

for (initialization; condition; update) {
    // Code block to be executed repeatedly as long as the condition is true
}

Explanation of the Syntax:

• JavaScript’s for loop operates similarly to other languages.
• It consists of an initialization expression, a loop condition, and an increment or decrement operation.
• The loop first executes the initialization part.
• It then evaluates the condition specified in the loop header.
• If the condition is true, the code block within the curly braces {} is executed.
• After executing the code block, the loop performs the increment or decrement operation.
• The loop returns to the loop header and re-evaluates the condition. If the condition remains true, the process continues; otherwise, the loop terminates.

Implementation of For loop Syntax in JavaScript:

Javascript

// For loop
for (let i = 0; i < 10; i++) {
    console.log(i + " ");
}

Output

0 
1 
2 
3 
4 
5 
6 
7 
8 
9