Difference Between While and Do While Loop
Introduction
While and Do While loops are used in programming languages to execute a set of statements repeatedly until a certain condition is met. These loops are essential in any programming language as they can automate repetitive tasks.
The While Loop
The While loop in programming is used to execute a block of code repeatedly as long as a particular condition is true. The syntax for a While loop is as follows:
“`
while(condition) {
//code to be executed repeatedly
}
“`
In a While loop, the condition is first checked, and if the condition is true, the statements inside the loop are executed. Once the statements are executed, the condition is checked again, and if it is still true, the statements will be executed again. This process continues until the condition becomes false, at which point the loop will terminate.
The Do-While Loop
The Do-While loop in programming is used to execute a block of code at least once, regardless of whether the condition is true or not. The syntax for a Do-While loop is as follows:
“`
do {
//code to be executed repeatedly
} while (condition);
“`
In a Do-While loop, the statements inside the loop are executed first, and then the condition is checked. If the condition is true, the statements inside the loop will be executed again. If the condition is false, the loop will terminate.
Differences Between While and Do-While Loop
The key difference between While and Do-While loops is that the While loop will only execute if the condition is true, while the Do-While loop will always execute at least once, even if the condition is false.
Another difference between these loops is the position of the conditional statement. In the While loop, the condition is checked before the statements are executed, while in the Do-While loop, the statements are executed before the condition is checked.
Conclusion
While and Do-While loops are necessary constructs in any programming language. While loops are useful when we’re unsure if code will execute more than once, and Do-While loops are useful when we need to ensure that the code executes once, no matter what. Understanding their differences allows developers to choose the most appropriate loop to use in their code.
Table difference between while and do while loop
| While Loop | Do While Loop |
|---|---|
| The loop condition is checked at the beginning of each iteration. | The loop condition is checked at the end of each iteration. |
| It might not execute the loop body if the condition is false from the beginning. | It executes the loop body at least once, even if the condition is false from the beginning. |
| It is used when we want to iterate a specific number of times. | It is used when we want to iterate until a specific condition is met. |