Difference Between While And Do While Loop

When it comes to programming, there are many different types of loops that can be used to execute a set of instructions multiple times. Two of the most commonly used loops are the while loop and the do-while loop. While both of these loops are used to execute a set of instructions multiple times, there are some key differences between the two that programmers should be aware of.

What Is a While Loop?

A while loop is a type of loop that will execute a set of instructions until a given condition is met. The syntax for a while loop is as follows:

while (condition) { // code to be executed }

The condition in the while loop can be any expression that evaluates to true or false. If the condition evaluates to true, the code inside the loop will be executed. If the condition evaluates to false, the loop will terminate and the program will move on to the next line of code.

What Is a Do-While Loop?

A do-while loop is a type of loop that will execute a set of instructions at least once, and then continue to execute the instructions until a given condition is met. The syntax for a do-while loop is as follows:

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do { // code to be executed } while (condition);

The condition in the do-while loop can be any expression that evaluates to true or false. If the condition evaluates to true, the code inside the loop will be executed. If the condition evaluates to false, the loop will terminate and the program will move on to the next line of code.

Difference Between While and Do-While Loops

The key difference between while and do-while loops is that a while loop will only execute its code if the condition evaluates to true, whereas a do-while loop will execute its code at least once, regardless of whether the condition evaluates to true or false.

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When to Use a While Loop

A while loop should be used when you want to execute a set of instructions until a given condition is met. For example, if you wanted to print out the numbers from 1 to 10, you could use a while loop like this:

int i = 1; while (i 
In this example, the condition is that the variable i is less than or equal to 10. As long as this condition is true, the code inside the loop will be executed. Once the condition evaluates to false (when i is greater than 10), the loop will terminate and the program will move on to the next line of code.
 
When to Use a Do-While Loop
 
A do-while loop should be used when you want to execute a set of instructions at least once, and then continue to execute the instructions until a given condition is met. For example, if you wanted to print out the numbers from 1 to 10, you could use a do-while loop like this:
 
int i = 1; do { System.out.println(i); i++; } while (i 
In this example, the condition is that the variable i is less than or equal to 10. The code inside the loop will be executed at least once, regardless of whether the condition evaluates to true or false. Once the condition evaluates to false (when i is greater than 10), the loop will terminate and the program will move on to the next line of code.
 
Advantages and Disadvantages of While and Do-While Loops
 
Both while and do-while loops have their advantages and disadvantages. The main advantage of a while loop is that it can be used to execute a set of instructions until a given condition is met. The main disadvantage of a while loop is that the code inside the loop may never be executed if the condition evaluates to false.
 
The main advantage of a do-while loop is that the code inside the loop will be executed at least once, regardless of whether the condition evaluates to true or false. The main disadvantage of a do-while loop is that it may lead to an infinite loop if the condition is always true.
 
Conclusion
 
In conclusion, while and do-while loops are both used to execute a set of instructions multiple times. The key difference between the two is that a while loop will only execute its code if the condition evaluates to true, whereas a do-while loop will execute its code at least once, regardless of whether the condition evaluates to true or false. Both while and do-while loops have their advantages and disadvantages, so it is important to choose the right loop for the job.
 

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