While Loop and Do While Loop are two important structures that are used in programming. They allow you to repeat a set of instructions multiple times. In this blog post, we will discuss the difference between While Loop and Do While Loop, and when to use each one.
What is While Loop?
While Loop is a type of loop that helps to execute a set of commands or instructions until the given condition is true. It checks the condition before executing the statements. While loop is an entry control loop which means that it tests the condition before entering into the loop body. If the condition is true, then only it enters into the loop body otherwise it skips the loop body. While loop can be used with any type of data type like int, float, char etc. We can also use While Loop to iterate over arrays and Strings.
While Loop is also known as a pre-tested loop because it tests the condition before executing the statements inside the loop body. While Loop syntax: While(condition) { // Statements } While(true) { // Statements } While(1) { // Statements } If we don’t provide any condition inside While loop then it will become an infinite loop and it will keep on executing the statements inside While Loop endlessly which may lead to system crash or hang. So, while using While Loop we should be very careful about the conditions that we provide inside it otherwise our program may go in to an infinite loop leading to system crash or hang.
What is Do-While Loop?
Do-While Loop is one of the three main programming structures. It is a type of loop that will execute a set of commands as long as a certain condition is true. The Do-While Loop structure looks like this: Do { Statements } While (condition); The Do-While Loop always execute the statements at least once before it checks the condition. This means that if the condition is never true, the statements will be executed forever.
It is important to make sure that the condition eventually becomes true, or else you will create an infinite loop. Do-While Loops are useful when you want to perform an action until a specific condition is met. For example, you might want to keep asking a user for input until they enter a valid answer. In this case, the input would be the condition, and the action would be to ask for input. Do-while loops are also known as pre-test loops because they check the condition before they execute the statements.
Difference Between While and Do-While Loop
The While loop tells the computer to do something as long as the condition is met. It checks the condition before executing the loop body. On the other hand, the Do-while loop first executes the body of the loop, and then it checks the condition. If you want to execute a set of statements based on a condition then you should use a While loop. If you want to execute a set of statements at least once, and then check for a condition, then you need to use a Do-while loop.
While loop is used when we don’t know how many times to iterate, on the other hand, do-while is useful when we need to iterate at least once. So, if our program requires iterations but we are not sure about how many times, it is advisable to use a While loop over the do-while loop. Also, in the case of Do-while even if the condition fails(i.e false), the body inside the do block is executed once whereas in the case of a while it is not executed even once if the condition fails first time itself.
Conclusion
The While Loop and Do While Loop are two types of loops in programming. They both have the same purpose, which is to repeat a certain set of code multiple times. However, there are some key differences between these two loops that you should be aware of before deciding which one to use in your own programs. Let’s take a look at those differences now.
