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JavaScript parseFloat() Function

Function Reference JavaScript Functions

Definition and Usage

The parseFloat() function parses a string and returns a floating point number.

This function determines if the first character in the specified string is a number. If it is, it parses the string until it reaches the end of the number, and returns the number as a number, not as a string.

Syntax

parseFloat(string)

Parameter Description
string Required. The string to be parsed

Tips and Notes

Note: Only the first number in the string is returned!

Note: Leading and trailing spaces are allowed.

Note: If the first character cannot be converted to a number, parseFloat() returns NaN.

Example

Example

In this example we will use parseFloat() to parse different strings:

<script type="text/javascript">

document.write(parseFloat("10") + "<br />");
document.write(parseFloat("10.00") + "<br />");
document.write(parseFloat("10.33") + "<br />");
document.write(parseFloat("34 45 66") + "<br />");
document.write(parseFloat(" 60 ") + "<br />");
document.write(parseFloat("40 years") + "<br />");
document.write(parseFloat("He was 40") + "<br />");

</script>

The output of the code above will be:

10
10
10.33
34
60
40
NaN

Try it yourself »

Function Reference JavaScript Functions

From http://www.w3schools.com (Copyright Refsnes Data)