Difference between for and while loop in C, C++, Java

Last Updated : 4 Sep, 2023

In C, C++, and Java, both for loop and while loop is used to repetitively execute a set of statements a specific number of times. However, there are differences in their declaration and control flow. Let's understand the basic differences between a for loop and a while loop.

for Loop

A for loop provides a concise way of writing the loop structure. Unlike a while loop, a for loop declaration consumes the initialization, condition, and increment/decrement in one line thereby providing a shorter, easy-to-debug structure of looping.

Syntax

for (initialization condition; testing condition; increment/decrement)
{
 // statement(s)
}

Flowchart of for Loop

👁 flowchart of for loop in C, C++ and Java

Example: Program to Demonstrate How to Use for Loop

Output

GFG
GFG
GFG
GFG
GFG

Looping Infinite Times

Output

GFG
GFG
GFG
...
...
...
{truncated}

while Loop

A while loop is a control flow statement that allows code to be executed repeatedly based on a given Boolean condition. The while loop can be thought of as a repeating if statement.

Syntax

while (boolean condition)
{
 // loop statements...
}

Flowchart of while Loop

👁 flowchart of while loop in C, C++ and Java

Example: CPP Program to Demonstrate while Loop

Output

GFG
GFG
GFG
GFG
GFG

Looping Infinite Times

Output

GFG
GFG
GFG
...
...
...
{truncated}

Difference Between for Loop and while Loop

The major differences between for loop and while loop in C, C++ and Java are as follows:

for Loop	while Loop
Initialization may be either in the loop statement or outside the loop.	Initialization is always outside the loop.
Once the statement(s) is executed then increment is done.	The increment can be done before or after the execution of the statement(s).
It is normally used when the number of iterations is known.	It is normally used when the number of iterations is unknown.
Condition is a relational expression.	The condition may be an expression or non-zero value.
It is used when initialization and updation of conditions are simple.	It is used for complex initialization.
For loop is entry controlled loop.	While loop is also entry controlled loop.
Syntax: for ( init ; condition ; iteration ) { statement(s); }	Syntax: while ( condition ) { statement(s); }
The for loop is used when the number of iterations is known.	The while loop is used when the number of iterations is unknown.