JavaScript parseFloat() Function
The JavaScript parseFloat() Function is used to accept the string and convert it into a floating-point number. If the string does not contain a numeral value or If the first character of the string is not a Number then it returns NaN i.e, not a number. It actually returns a floating-point number parsed up to that point where it encounters a character that is not a Number.
Syntax:
parseFloat(Value)
Parameters: This function accepts a single parameter as mentioned above and described below:
- value: This parameter obtains a string that is converted to a floating-point number.
Return value: It returns a floating-point Number and if the first character of a string cannot be converted to a number then the function returns NaN i.e, not a number.
Below is an example of the parseFloat() function.
Example 1:
javascript
<script> var v2 = parseFloat("3.14"); console.log('Using parseFloat("3.14") = ' + v2);</script> |
Output:
Using parseFloat("3.14") = 3.14Example 2: The parseFloat() function ignores leading and trailing spaces and returns the floating point Number of the string.
Input : var n = parseFloat(" 2018 ");
Output: n=2018 (floating point Number)Example 3:
Input: var a = parseFloat("1000.04");
Output:now a = 1000.04(floating point Number)More example codes for the above function are as follows:
Program 1:
javascript
<script> // It ignores leading and trailing spaces. a = parseFloat(" 100 ") console.log('parseFloat(" 100 ") = ' +a); // It returns floating point Number until // it encounters Not a Number character b = parseFloat("2018@geeksforgeeks") console.log('parseFloat("2018@geeksforgeeks") = ' +b); // It returns NaN on Non numeral character c = parseFloat("geeksforgeeks@2018") console.log('parseFloat("geeksforgeeks@2018") = ' +c); d = parseFloat("3.14") console.log('parseFloat("3.14") = ' +d); // It returns only first Number it encounters e = parseFloat("22 7 2018") console.log('parseFloat("22 7 2018") = ' +e);</script> |
Output:
parseFloat(" 100 ") = 100
parseFloat("2018@geeksforgeeks") = 2018
parseFloat("geeksforgeeks@2018") = NaN
parseFloat("3.14") = 3.14
parseFloat("22 7 2018") = 22Program 2: Using the isNaN() function to test whether the converted values are a valid numbers or not.
javascript
<script> var x = parseFloat("3.14"); if (isNaN(x)) console.log("x is not a number"); else console.log("x is a number"); var y = parseFloat("geeksforgeeks"); if (isNaN(y)) console.log("y is not a number"); else console.log("y is a number"); // Difference between parseInt() and parseFloat() var v1 = parseInt("3.14"); var v2 = parseFloat("3.14"); console.log('Using parseInt("3.14") = ' + v1); console.log('Using parseFloat("3.14") = ' + v2);</script> |
Output:
x is a number
y is not a number
Using parseInt("3.14") = 3
Using parseFloat("3.14") = 3.14We have a complete list of Javascript Function methods, to check those please go through this Javascript Function Complete reference article.
Supported Browsers:
- Google Chrome 1 and above
- Edge 12 and above
- Firefox 1 and above
- Internet Explorer 3 and above
- Safari 1 and above
- Opera 3 and above
We have a Cheat Sheet on Javascript where we covered all the important topics of Javascript to check those please go through Javascript Cheat Sheet-A Basic guide to JavaScript.
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