Boolean is a primitive datatype in JavaScript. It is also used as a function which returns only two values, either true or false.
Table of Contents
Boolean() Function in JavaScript
The Boolean() function is used to get the Boolean value of any variable or object. It is also used in conditional statements or expressions to evaluate their truthiness.
Any variable or object that contains a value is treated as true; while others like 0, NaN, empty string, undefined, null are all treated as false.
Code #01
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<p id="demo1"></p>
<p id="demo2"></p>
<p id="demo3"></p>
<p id="demo4"></p>
<p id="demo5"></p>
<p id="demo6"></p>
<p id="demo7"></p>
<p id="demo8"></p>
<script>
b1 = Boolean(10);
b2 = Boolean("CodeLeaks");
b3 = Boolean(3.14);
b4 = Boolean(-1);
b5 = Boolean("true");
b6 = Boolean("false");
b7 = Boolean([]);
b8 = Boolean(3 > 1);
document.getElementById("demo1").innerHTML = "Boolean(10) = " + b1;
document.getElementById("demo2").innerHTML = "Boolean('CodeLeaks') = " + b2;
document.getElementById("demo3").innerHTML = "Boolean(3.14) = " + b3;
document.getElementById("demo4").innerHTML = "Boolean(-1) = " + b4;
document.getElementById("demo5").innerHTML = "Boolean('true') = " + b5;
document.getElementById("demo6").innerHTML = "Boolean('false') = " + b6;
document.getElementById("demo7").innerHTML = "Boolean([]) = " + b7;
document.getElementById("demo8").innerHTML = "Boolean(3 > 1) = " + b8;
</script>
</body>
</html>
Output
Code#02
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<p id="demo1"></p>
<p id="demo2"></p>
<p id="demo3"></p>
<p id="demo4"></p>
<p id="demo5"></p>
<p id="demo6"></p>
<p id="demo7"></p>
<p id="demo8"></p>
<script>
b1 = Boolean(0);
b2 = Boolean("");
b3 = Boolean();
b4 = Boolean(-0);
b5 = Boolean(NaN);
b6 = Boolean(false);
b7 = Boolean(null);
b8 = Boolean(3 < 1);
document.getElementById("demo1").innerHTML = "Boolean(0) = " + b1;
document.getElementById("demo2").innerHTML = "Boolean('') = " + b2;
document.getElementById("demo3").innerHTML = "Boolean() = " + b3;
document.getElementById("demo4").innerHTML = "Boolean(-0) = " + b4;
document.getElementById("demo5").innerHTML = "Boolean(NaN) = " + b5;
document.getElementById("demo6").innerHTML = "Boolean(false) = " + b6;
document.getElementById("demo7").innerHTML = "Boolean(null) = " + b7;
document.getElementById("demo8").innerHTML = "Boolean(3 < 1) = " + b8;
</script>
</body>
</html> Output
Conclusion
In this article, we discussed JavaScript Boolean primitive datatype. It gives us two values, true or false. Boolean() is a function in which we pass the values whose truth value we want to know. We also saw two examples, the first one was returning true for all values passed in the method; and the second one returned false for all the passed values.
