Course Content
Introduction to JavaScript
Introduction to JavaScript
while
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:
let a = 5; while (a <= 10) { console.log("a =", a); a++; }
In this example, the while
loop's code block executes six times:
- Initially, the variable
a
is set to5
; - 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 initiallyfalse
, 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.
Everything was clear?