# How to convert a value to a number in JavaScript?

In this article we are going to discuss how to convert a value to a number in JavaScript.

JavaScript has introduced Number(), parseInt(), parseFloat() methods to convert a value into a number and also we can achieve it by using (+) unary operator. These mentioned methods can convert number strings to numbers and Boolean values to 1's or 0's. Let’s us discuss these above mentioned methods briefly.

We’ll discuss the 4 possible ways to convert a value to a number with an example each.

• Number()

• parseInt()

• parseFloat()

• Unary Opertaor(+)

### Example 1

The following is an example program to convert a value to a number using Number() method.

<!DOCTYPE html>
<html>
<title>To convert a value to a number in JavaScript</title>
<body style="text-align : center">
<h3></h3>
<p id='valToNum'>To convert a value to a number in JavaScript using Number()</p>
<script>
let a = Number("100");
let b = Number("100.234");
let c = Number(true); //return 0 or 1 for boolean
let d = Number("true"); //returns a number or NaN
let e = Number(new Date()); //returns number of milli seconds from Jan 1 1970
let f = Number([1.2]);
document.getElementById('valToNum').innerHTML = Number("100") is ${a}${'<br/>'} Number("100.234") is ${b}${'<br/>'} Number(true) is ${c}${'<br/>'} Number("true") is ${d}${'<br/>'} Number(new Date()) is ${e}${'<br/>'} Number([1.2]) is {f} ; </script> </body> </html>  On executing the above code, the following output is generated. ### Example 2 The following is an example program to convert a value to a number using parseInt() method. <!DOCTYPE html> <html> <head> <title>To convert a value to a number in JavaScript</title> </head> <body style="text-align : center"> <h3></h3> <p id='valToNum'>To convert a value to a number in JavaScript using parseInt()</p> <script> //ParseInt() parses a string and returns a whole number, else NaN. let a = parseInt("100"); let b = parseInt("100.234"); let c = parseInt([1.2]); let d = parseInt(true); document.getElementById('valToNum').innerHTML = parseInt("100") is{a} ${'<br/>'} parseInt("100.234") is${b} ${'<br/>'} parseInt([1.2]) is${c} ${'<br/>'} parseInt(true) is${d} ;
</script>
</body>
</html>


On executing the above code, the following output is generated.

### Example 3

The following is an example program to convert a value to a number using parseFloat() method.

<!DOCTYPE html>
<html>
<title>To convert a value to a number in JavaScript</title>
<body style="text-align : center">
<h3>To convert a value to a number in JavaScript using parseFloat()</h3>
<p id='valToNum'></p>
<script>
//ParseFloat() parses a string and returns a Number.
let a = parseFloat("100");
let b = parseFloat("100.234");
let c = parseFloat([1.2]);
let d = parseFloat(true);
document.getElementById('valToNum').innerHTML = parseFloat("100") is ${a}${'<br/>'} parseFloat("100.234") is ${b}${'<br/>'} parseFloat([1.2]) is ${c}${'<br/>'} parseFloat(true) is {d} ; </script> </body> </html>  On executing the above code, the following output is generated. ### Example 4 The following is an example program to convert a value to a number using unary operator(+). <!DOCTYPE html> <html> <head> <title>To convert a value to a number in JavaScript</title> </head> <body style="text-align : center"> <h3>To convert a value to a number in JavaScript using Unary operator</h3> <p id='valToNum'></p> <script> // Unary operator converts a string to a Number. let a = +"100"; let b = +"-100.234"; let c = +[1.2]; document.getElementById('valToNum').innerHTML = +"100" is{a} ${'<br/>'} +"-100.234" is${b} ${'<br/>'} +[1.2] is${c} \${'<br/>'} ;
</script>
</body>
</html>


On executing the above code, the following output is generated.