JavaScript Number toPrecision( ) Method
Below is the example of the Number toPrecision( ) Method.
- Example:
<
script
type
=
"text/javascript"
>
var num=213.45689;
document.write(num.toPrecision(3));
</
script
>
- Output:
213
The toPrecision() method in Javascript is used to format a number to a specific precision or length. If the formatted number requires more digits than the original number then decimals and nulls are also added to create the specified length.
Syntax:
number.toPrecision(value)
The toPrecision() method is used with a number as shown in above syntax using the ‘.’ operator. This method will format a number to a specified length.
Parameters: This method accepts a single parameter value. This parameter is also optional and it represents the value of the number of significant digits the user wants in the formatted number.
Return Value: The toPrecision() method in JavaScript returns a string in which the number is formatted to the specified precision.
Below are some examples to illustrates toPrecision() method:
- Passing no arguments in the toPrecision() method: If no arguments is passed to the toPrecision() method then the formatted number will be exactly the same as input number. Though, it will be represented as a string rather than a number.
Code# 1:<
script
type
=
"text/javascript"
>
var num=213.45689;
document.write(num.toPrecision());
</
script
>
Output:
213.45689
- Passing an argument in the toPrecision() method: If the length of precision passed to the toPrecision() method is smaller than the original number then the number is rounded off to that precision.
Code# 2:<
script
type
=
"text/javascript"
>
var num=213.45689;
document.write(num.toPrecision(4));
</
script
>
Output:
213.5
- Passing an argument which results in addition of null in the output: If the length of precision passed to the toPrecision() method is greater than the original number then zero’s are appended to the input number to meet the specified precision.
Code# 3:<
script
type
=
"text/javascript"
>
var num=213.45689;
document.write(num.toPrecision(12));
var num2 = 123;
document.write(num2.toPrecision(5));
</
script
>
Output:
213.456890000 123.00
Note: If the precision specified is not in between 1 and 100 (inclusive), it results in a RangeError.
Supported Browsers:
- Google Chrome 1 and above
- Internet Explorer 5.5 and above
- Firefox 1 and above
- Apple Safari 2 and above
- Opera 7 and above