Loop Javascript

Michael Zippo 04.11.2021

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do‚Ä¶ while loops can be used to execute a block of code once and will continue to execute if an instruction continues to evaluate as true. The while and do ... while loops are useful if you want to execute a block of code when a certain condition is met.

Loops are a fundamental feature of programming and are used to automate similar tasks. For example, suppose you want to print each name in a list of students. You can create a loop to automate the task.

JavaScript provides two main types of loops that can be used to perform a task that is repetitive multiple times. The first type, called a for loop, executes a statement a number of times. The second type is the while loop, which is executed depending on whether a condition is true or not.

In this tutorial, we’ll cover the basics of the while loop in JavaScript. We’ll explore the syntax of while loops, how to create do‚Ä¶ while loops, and explore some examples of these loops in action.

JavaScript While Loops

A JavaScript while loop executes a block of code while a condition evaluates to true. While loops stop executing when their condition is false. A while loop allows you to repeat a block of code multiple times without copying and pasting the code.

while loops are often used if you want to execute unspecified code multiple times. On the other hand, JavaScript for loop are used if you already know or can calculate how many times your loop should run.

Here is the syntax of a while loop in JavaScript:

The while statement is very similar to a JavaScript for .

You can create an infinite loop by specifying a condition that will always evaluate as true. Make sure your condition can be evaluated as false unless you want the loop to continue until you manually abort planning.

While JavaScript Loop Example

Let’s say we’re having an exclusive party. We want to invite only 40 people to our party at one time.

There are already 35 people at our party. Every time we invite someone, we want to calculate how many more people we can invite before we reach the limit. Here is an example of a program that uses an while loop to perform this calculation:

Our code returns the following:

In the first two lines of our code, we declare two variables. The limit variable is used to specify the maximum number of people that can join our group. The current_attendees JavaScript variable keeps track of how many people are currently attending the party.

Let’s create a while loop that runs until the number of current participants is less than the limit we set.

Next, our program adds 1 to the number of current participants and calculates the number of spaces remaining by subtracting current_attendees from limit. Finally, our program prints a statement to the console telling our group leader how many spaces are left.

Our cycle then lasted as long as there were less than 40 people in our group. Each time the loop ran, our current_attendees increased by 1. As soon as our group reached 40 participants, our loop stopped working.

while loops: Another example

Let’s use another example to illustrate the while loop in action. In the following example, we create a while loop that prints each name in our VIP party table:

Our code returns:

Our loop iterates through the vips array until our counter variable is less than the length of the JavaScript table .

JavaScript do‚Ä¶ while Loop
A JavaScript do‚Ä¶ while loop executes a statement once, then checks if a condition is true. If the condition is true, the loop will execute again. Otherwise, the code no longer works.

There is a big difference between a while loop and a do‚Ä¶ while loop. Do ... while loops are executed at least once even if the specified condition never evaluates to true. In contrast, while loops are only executed if their condition is true.

Here is the syntax of a do‚Ä¶ while loop in JavaScript:

The code in our do‚Ä¶ while loop will always be executed at least once.

JavaScript do‚Ä¶ while loop example

Let’s use an example to illustrate how the do‚Ä¶ while loop works. Let’s say we create a puzzle. We want our program to keep asking a user to guess a number until they guess the correct number.

Here is an example of a program that we could use to create this puzzle:

Our program will ask the user to enter a number between 1 and 10 as long as guessed_number is not equal to < em> number_to_guess. But our program will execute the contents of our do statement before evaluating the conditions for the first time.

When our condition is false, our loop will stop executing.

Conclusion

While loops can be used to execute a repetitive block of code while a statement evaluates to true. Do‚Ä¶ while loops can be used to execute a block of code once. They will continue to function if an instruction continues to return true.

The while and do‚Ä¶ while loops are useful if you want to execute a block of code when a certain condition is met.

In this tutorial, we have explained how to create a while and do‚Ä¶ while loop in JavaScript. We’ve also explored a few examples of these loops in action to illustrate where they can be useful. Now you have the information you need to use the while loop like a JavaScript expert !

For tips on the best JavaScript learning resources and courses, see our Article on how to learn JavaScript .

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We hope this article has helped you to resolve the problem. Apart from Loop Javascript, check other __main__ Python module-related topics.

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