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JavaScript true false | Boolean Basics

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The Javascript standard defines true and false values using a boolean data type. Javascript booleans may be true, false, or (in certain contexts) a value that evaluates to either true or false.

let a = true;
let b = false;

Use the reserved keywords true or false to assign a boolean value to a variable.

let str = "true";             // Incorrect: not a boolean.
let obj = new Boolean(true);  // Incorrect: overcomplicated.

Note: Don’t specify a boolean value as a string or as an object.

JavaScript true false

A simple example code demonstrates how a boolean value controls the program flow using the if condition.

<!DOCTYPE html>
   var YES = true;
   var NO = false;

    console.log("This code block will be executed");

    console.log("This code block will not be executed");


JavaScript true false

The comparison expressions return boolean values to indicate whether the comparison is true or false.

var a = 10, b = 20;

var result = 1 > 2; // false

result = a < b; // true

result = a > b; // false

result = a + 20 > b + 5; // true

Do comment if you have any doubts or suggestions on this Js basic topic.

Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.

OS: Windows 10

Code: HTML 5 Version

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