JavaScript Number Methods

Many JavaScript Number methods are commonly used to manipulate number values. These number formats accept integers and floating-point numbers in decimal and hexadecimal notations.

Here are a few techniques for manipulating and modifying numerical values.

Method	Description
toString()	Converts a number to a string.
toExponetial()	Convert a number into exponential notation.
toFixed()	Formats a number with a specified number of decimal places.
toPrecision()	Formats a number with a specified number of significant digits.
ValueOf()	Returns the primitive value of a number.
Number()	Convert a value to a number.
parseInt()	Convert a string to an integer.
parseFloat()	Convert a string to a floating-point number.
Number.isInteger()	Determines whether a value is an integer or not.
Number.isSafeInteger()	Determines whether a value is a safe integer or not.
Number.parseFloat()	Convert a string to a floating-point number.
Number.parseInt()	Convert a string to an integer.

1. toString()

The toString() method is a built-in method in JavaScript that is used to convert a number to a string.

Example

<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Number toString()</h1>
<script>
    var num = 123;
    var result = num.toString();
    document.write(result + "<br>");

    var result2 = (123).toString();
    document.write(result2);
</script>

</body>
</html>

Preview

2. toExponential()

The toExponential() method is a built-in method in JavaScript that is used to Convert a number into exponential notation.

Example

<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Number toExponential()</h1>
<script>
    var num = 123.45;

    var result = num.toExponential();
    document.write(result + "<br>");

    var result2 = num.toExponential(2);
    document.write(result2);
</script>

</body>
</html>

Preview

3. toFixed()

The toFixed() method is a built-in JavaScript method that is used to convert a number to a string and round the number to a specified number of decimal places.

Example

<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Number toFixed()</h1>
<script>
    var num = 123.45;

    var result = num.toFixed();
    document.write(result + "<br>");

    var result2 = num.toFixed(2);
    document.write(result2);
</script>

</body>
</html>

Preview

4. toPrecision()

The toPrecision() method is a built-in JavaScript method that is used to convert a number to a string and format it to a specified number of significant digits.

Example

<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Number toPrecision()</h1>
<script>
    var num = 123.45;

    var result = num.toPrecision();
    document.write(result + "<br>");

    var result2 = num.toPrecision(2);
    document.write(result2);
</script>

</body>
</html>

Preview

5. ValueOf()

The valueOf() method is a built-in JavaScript method that returns the primitive value of an object.

Example

<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Number valueOf()</h1>
<script>
    var num = 123;

    var result = num.valueOf();
    document.write(result + "<br>");

    var result2 = num.valueOf(2);
    document.write(result2);
</script>

</body>
</html>

Preview

6. Number()

The Number() function is a built-in function in JavaScript that can be used to Convert a value to a number.

Example

<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Number()</h1>
<script>
    document.write(
        Number(true) + "<br>" +
        Number(false) + "<br>" +
        Number("12") + "<br>" +
        Number("12.34") + "<br>" +
        Number("12,34") + "<br>" +
        Number("Peter")
    )
</script>

</body>
</html>

Preview

7. parseFloat()

The parseFloat() function is a built-in function in JavaScript that is used to Convert a string to a floating-point number.

Example

<!DOCTYPE html>
<html>
<body>

<h1>JavaScript parseFloat()</h1>
<script>
    document.write(
        parseFloat("12") + "<br>" +
        parseFloat("-12") + "<br>" +
        parseFloat("12.34") + "<br>" +
        parseFloat("-12.34") + "<br>" +
        parseFloat("2022 years") + "<br>" +
        parseFloat("years 2023")
    )
</script>

</body>
</html>

Preview

8. parseInt()

The parseInt() function is a built-in function in JavaScript that is used to convert a string to an integer.

Example

<!DOCTYPE html>
<html>
<body>

<h1>JavaScript parseInt()</h1>
<script>
    document.write(
        parseInt("12") + "<br>" +
        parseInt("-12") + "<br>" +
        parseInt("12.34") + "<br>" +
        parseInt("-12.34") + "<br>" +
        parseInt("2022 years") + "<br>" +
        parseInt("years 2023")
    )
</script>

</body>
</html>

Preview

9. Number.isInteger()

The Number.isInteger() is a built-in function in JavaScript that determines whether a value is an integer or not.

Example

<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Number.isInteger()</h1>
<script>
    document.write(
        Number.isInteger(12) + "<br>" +
        Number.isInteger(12.34)
    )
</script>

</body>
</html>

Preview

10. Number.isSafeInteger()

The Number.isSafeInteger() is a built-in function in JavaScript that determines whether a value is a safe integer or not.

Example

<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Number.isSafeInteger()</h1>
<script>
    document.write(
        Number.isSafeInteger(12) + "<br>" +
        Number.isSafeInteger(12.34567890)
    )
</script>

</body>
</html>

Preview

11. Number.parseFloat()

The Number.parseFloat() is a built-in function in JavaScript that is used to convert a string to a floating-point number.

Example

<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Number.parseFloat()</h1>
<script>
    document.write(
        Number.parseFloat("12") + "<br>" +
        Number.parseFloat("-12") + "<br>" +
        Number.parseFloat("12.34") + "<br>" +
        Number.parseFloat("-12.34") + "<br>" +
        Number.parseFloat("2022 years") + "<br>" +
        Number.parseFloat("years 2023")
    )
</script>

</body>
</html>

Preview

12. Number.parseInt()

The Number.parseInt() is a built-in function in JavaScript that is used to convert a string to an integer.

Example

<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Number.parseInt()</h1>
<script>
    document.write(
        Number.parseInt("12") + "<br>" +
        Number.parseInt("-12") + "<br>" +
        Number.parseInt("12.34") + "<br>" +
        Number.parseInt("-12.34") + "<br>" +
        Number.parseInt("2022 years") + "<br>" +
        Number.parseInt("years 2023")
    )
</script>

</body>
</html>

Preview

JS Numbers

JS Numbers Properties

JavaScript Number Methods

1. toString()

Example

2. toExponential()

Example

3. toFixed()

Example

4. toPrecision()

Example

5. ValueOf()

Example

6. Number()

Example

7. parseFloat()

Example

8. parseInt()

Example

9. Number.isInteger()

Example

10. Number.isSafeInteger()

Example

11. Number.parseFloat()

Example

12. Number.parseInt()

Example

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