Just use the literal values, true or false to declare Boolean in JavaScript. You should never create a boolean using the Boolean constructor function because new Boolean(false) returns an object.
Normally JavaScript booleans are primitive values created from literals:
let x = false;But booleans can also be defined as objects with the keyword new:
let y = new Boolean(false);Keep in mind that Boolean values are case-sensitive, so true and false must be in lowercase. Additionally, JavaScript is loosely typed, meaning you can reassign values of different types to a variable. For example:
var myBoolean = true;
myBoolean = false; // Reassigning with a different Boolean value
myBoolean = "hello"; // Reassigning with a string (not recommended)
While the above is technically possible, it’s considered good practice to maintain the intended type of a variable throughout your code.
Declare Boolean in JavaScript
Simple example code.
<!DOCTYPE html>
<html>
<body>
<script>
let x = false;
let y = new Boolean(false);
console.log(typeof(x), x);
console.log(typeof(y), y);
</script>
</body>
</html> Output:
Creating Boolean objects with an initial value of false
var bNoParam = new Boolean();
var bZero = new Boolean(0);
var bNull = new Boolean(null);
var bEmptyString = new Boolean('');
var bfalse = new Boolean(false);
Creating Boolean objects with an initial value of true
var btrue = new Boolean(true);
var btrueString = new Boolean('true');
var bfalseString = new Boolean('false');
var bSuLin = new Boolean('Su Lin');
var bArrayProto = new Boolean([]);
var bObjProto = new Boolean({});
Comment if you have any doubts or suggestions on this JS boolean example code.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version