20+ Difference between For Loop And While Loop

Repeatedly running a program’s instructions is accomplished with the help of iteration statements like for loops and while loops in programming languages.

While the program runs, the statements are executed repeatedly using both for loops and while loops.

In contrast to the while loop, which continues to execute until the statement in the program is proven false, the for loop is used when the number of iterations is known.

Comparison Between For Loop And While Loop

ParameterFor LoopWhile Loop
DefinitionJava supports two distinct iterations of the for loop, which may be utilized in programming. For your consideration and choice, both the “standard” version and the “for-each” form are included in this presentation.The while loop is an important component in building control structures in both C++ and Java. Both of these programming languages are examples of concurrent programming languages. The while loop is implemented in C++ and Java in ways that are surprisingly similar to one another in terms of the features that are included in each.
InitializationThe loop’s initialization may occur either inside the loop statement itself or in a separate statement located within or outside it. There is a possibility that one of these many interpretations is the correct one.It is highly recommended that, where it is feasible to do so, the initialization function be moved to a position that is distinct from the main loop. This is something that should be done whenever it is practicable to do so.
IncrementThe increment does not occur until after the statement or statements have finished being run; only at this point does it become active and begin to take effect. In other words, the increase does not occur until after the statement or statements are executed.You can execute the price increase before or after the statement has been completed, depending on which choice caters to your requirements and preferences most efficiently.
UsesUsing this method will likely make it feasible for one to accomplish the intended goal, but, to do so, one must first calculate the required number of repetitions. Even while there is a chance that something may be successful, there is no guarantee that it will be.If you are unsure about the exact number of times an iteration should be carried out, consult with this tool since it can help you estimate the best frequency for carrying out the iteration.
Iteration statementWhen working with a ‘for’ loop, the iteration statement is always added at the end of the loop after all the other statements contained within the loop have been executed. This is done so that the statement can be carried out after the loop has completed all the other statements.An iteration statement may be changed back to its original function at any point in time while the “while” loop is being executed. This can happen at any stage in the process.

The Major Difference Between For Loop And While Loop

What exactly is Loop?

Users of the for loop have a much simpler time when it comes to representing the loop structure in code due to them being a loop.

In contrast to the while loop, the for statement provides a looping structure that is more compact, straightforward, and fundamental.

In addition to that, finding and fixing bugs is simple. You might verify the condition on a single line, do the initialization on the same line, and then either decrement or increase the value afterward.

Key Difference: For Loop

  • Akin to an assignment statement, the initialization gets things going. A loop control variable may be initialized using this. 
  • A phrase of a relational nature is used as the condition. When this condition is met, the loop will terminate. 
  • A block of statements or no statements may be placed within the for loop’s body. The iteration statement is written at the beginning of a ‘for’ loop. 
  • This means that the iteration statement won’t be run until after everything else has finished. Initialization is only done once in the ‘for’ loop. 
  • If the ‘for’ loop’s condition isn’t met, the loop will keep repeating forever. The ‘for’ statement should be used instead of the ‘while’ statement if you have a certain number of iterations in mind. 
  • The for loop’s conditional statement, initialization, and iteration are all written on top of the loop. Each iteration of the for loop causes the condition to be evaluated. 
  • The for loop’s controlling variable is initialized once, and only once, throughout the loop’s execution. This occurs on the first pass through a loop. 
  • The initialization condition is fulfilled before the condition is verified each time the loop instruction is carried out.

What Exactly Is While Loop?

While loops are a specialized form of control flow statement that can be used to execute a section of code multiple times depending on the value that is returned by a boolean expression, this can be accomplished by comparing the value that is returned by the expression to the value that is returned by the while loop.

One way to conceive of a while loop is as an iterative if statement. This is one way to think about it.

Key Difference: While Loop

  • Only the while loop’s condition is checked and initialized outside the loop. The’ while’ loop is the best option without a hard-coded limit on the number of loop iterations. 
  • A compilation error will be produced if the condition is missing from the ‘while’ loop. 
  • In case the initialization is performed at the step of condition testing, like in the case of the ‘while’ loop. Each iteration of the loop requires a fresh round of setup. 
  • The statement to be executed during each iteration of the ‘while’ loop may be written at any point inside the loop. Any kind of phrase may be used as the ‘while’ loop’s condition. 
  • If a value other than zero is returned, then it is true. While the specified condition is true, the loop will continue to execute. 
  • Whenever the condition of the loop is no longer true, execution will go to the next line of code in the program. 
  • The while loop performs an initial condition check and then runs the statements inside it until the condition is no longer true. 
  • Any boolean expression may be used for the while loop’s associated criteria. If a value other than zero is returned, the condition holds true; otherwise, it is false.


  • For Loop – Using a for loop allows for a clear and succinct structure in a computer programming language.

    In other words, it’s a statement used to regulate admission into a database. The for loop is used to execute a statement several times.

    They help keep the code sizes down. The for loop tests the specified condition iteratively, and execution continues until the goal is achieved.
  • While Loop – Using a while loop is another option for recreating the results of a previous statement’s execution.

    The number of times this loop will iterate is essentially unbounded as long as the goal or condition specified in the given statement has not been reached. The language that is used to construct computer programs has a very fundamental loop in its syntax.


  • For Loop – First, you write the statements that do any necessary setup, condition checking, and iteration. It’s only useful if you know exactly how many iterations you’ll need.

    An unlimited number of times will be cycled through the loop if the condition is not specified in the ‘for’ statement.

    There is only ever a single round of initialization performed. The statement of iteration is presented first. Therefore, it runs after the loop’s statements have finished executing.
  • While Loop – At the start of the loop, we do any necessary setup and condition testing. Only when the total number of iterations is unknown is this method used.

    The compilation will fail if the condition is not specified inside the ‘while’ loop. If initialization is performed when the condition is verified, it will be executed at each iteration of the loop. Any part of the loop is OK for inserting the iteration statement.

How it works:

  • For Loop – During each iteration of the loop, the initialization condition is executed before the condition itself is checked for accuracy.

    The loop’s body is executed, and then the iteration statement is carried out, but only if the condition has a positive evaluation.

    Going all the way back to the beginning, the condition is examined once more to determine whether or not the loop will remain active or exit.
  • While Loop – First, the condition that controls the loop’s initialization is executed, and only after that is the condition itself put to the test.

    Assuming all preconditions are met, the iteration statement is run first. The condition is rechecked to see whether the loop will continue to repeat as normal or if it will exit the loop.

Where to use:

  • For Loop – Following the completion of the execution of the iteration statement inside the main body of the execution of the for loop, the execution of the iteration statement will begin within the upcoming step of the loop.

    This will take place once the execution of the iteration statement that is included inside the main body of the for loop’s execution has reached its conclusion.
  • While Loop – However, loops allow iteration statements to be placed anywhere in their bodies, which means that subsequent statements in the loop’s body can run after the iteration statement has finished executing.

    This contrasts loops, which do not permit iteration statements to be placed anywhere in their bodies. For loops, on the other hand, which do not allow iteration statements to be put anywhere in their bodies, this is in contrast.


  • For Loop – The iteration variable is preceded by the “type” argument, which indicates the kind of iteration variable to use. The iteration variable will get the item from the collection variable.

    All the collection variable’s items must be of the same type; hence the type must be correct.

    The iteration of the for loop may be automated from start to finish by using the for-each variant of the for loop, which accesses the data in the specified range in sequential order.
  • While Loop – The statements within a while loop are executed only if the condition contained inside the while loop evaluates to true, any boolean expression may be used as the condition in a while loop.

    If the result of an expression is greater than zero, then the condition holds; otherwise, it fails.

Frequently Asked Questions (FAQs)

Q1. What causes a loop to be created?

They come into existence when there is a malfunction in the operation of the routing algorithm, which leads to the formation of a loop in the route that leads to a certain destination from a collection of nodes.

A loop connection between devices is what creates a physical loop in a system. A typical illustration of this would be two switches that are connected to each other via two active Ethernet lines.

Q2. Could you further elaborate on what you mean by “nested loops”?

A nested loop is a loop statement that is included inside another loop statement. Nested loops are referred to by the acronym NLOOP.

Because of this, nested loops are sometimes called “loops inside loops” (loops within loops).

Any restriction does not limit the potential number of loops that may be formed inside another loop.

Q3. What precisely is the goal of using loops in this manner?

A loop is a structure in computer programming that iteratively executes a series of instructions until a predetermined criterion is satisfied.

The criterion can be anything from simple to complex. Instead of having to recreate the same set of instructions every time you want your computer to carry out a task, you can use a loop to repeat the procedure over and again automatically.

This is a time-saver and guarantees quality results. As a consequence, you’ll spend less time fixing errors and more time reaping the benefits.

Q4. What is the most effective iteration of the loop in the Python programming language?

Utilizing the built-in functions that are included as part of the standard distribution of the Python programming language is one of the simplest ways to loop in Python.

If we were to apply this reasoning to our example, we might come to the conclusion that the sum function is more appropriate than the for loop in this situation.

Using this function will result in calculating the total sum of all the values that fall within the parameters of the given number range.

Q5. Does the for loop ever come to an end when it reaches nothing?

If we do want, we may make a loop that repeats itself endlessly by using empty sentences to form the loop.

On the other hand, if we introduce break statements within the body of the loop, then the loop will be able to escape on its own at the end of the execution of the code.

It is possible to use an empty statement to build a for-loop or while-loop that does not execute any code. This will allow us to create the loop.

Similar Posts:

Was this article helpful?

Leave a Comment