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Introduction to JavaScript

whilewhile

Loop Types

Loops are structures that repeatedly execute a code block while a specific condition is true. In JavaScript, there are three types of loops:

  • while
  • do-while
  • for

Let's explore each of them in detail.

while Loop

The while loop is the simplest type of loop. It continues to execute a code block as long as the specified condition remains true.

To create a while loop, use the while keyword followed by a condition in parentheses and enclose the code block in curly braces. The syntax is similar to that of an if statement:

Here's an example:

In this example, the while loop's code block executes six times:

  • Initially, the variable a is set to 5.
  • The loop condition is a <= 10, which is true, so the code block is executed.
  • After each execution, the variable a is incremented by 1.
  • The loop continues to execute as long as the condition remains true.

Note

The while loop checks the condition before executing the code block. If the condition is initially false, the code block will not be executed.

Note

Be cautious with the condition! If the condition always evaluates to true, the loop will never break, resulting in an infinite loop, which can cause your program to hang or become unresponsive.

1. How many times will the program output "Hello!"?
2. How many times will the program output "JavaScript"?
3. How many times will the program output "Be careful!"

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How many times will the program output "Hello!"?

Select the correct answer

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How many times will the program output "JavaScript"?

Select the correct answer

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How many times will the program output "Be careful!"

Select the correct answer

Everything was clear?

Section 5. Chapter 1