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# Floating point number precision in JavaScript

• Last Updated : 20 May, 2019

The representation of floating points in JavaScript follows the IEEE-754 format. It is a double precision format where 64 bits are allocated for every floating point. The displaying of these floating values could be handled using 2 methods:

Using toFixed() Method: The number of decimal places in float values can be set using the toFixed() method. This method converts the number into a string, keeping the specified number of digits after the point. If no value is passed as a parameter, then it takes 0 as default value i.e. no decimal points are displayed.

Syntax:

`number.toFixed(digits)`

Example:

 ```<``html``>``     ` `<``head``>``    ``<``title``>``        ``Floating point number precision``        ``in JavaScript?``    `````` ` `<``body``>``    ``<``h1` `style``=``"color: green"``>``        ``GeeksforGeeks``    ````     ` `    ``<``b``>``        ``Floating point number precision``        ``in JavaScript?``    ````     ` `    ``<``p``>``        ``Original floating point: 3.14159265359``    ````     ` `    ``<``p``>``        ``Floating point when decimal places set``        ``to 2: <``span` `class``=``"output-2"``>``    ````     ` `    ``<``p``>``        ``Floating point when decimal places set``        ``to 5: <``span` `class``=``"output-5"``>``    ```` ` `    ``<``button` `onclick``=``"setDecimalPlaces()"``>``        ``Change decimal points``    ````     ` `    ``<``script` `type``=``"text/javascript"``>``        ``function setDecimalPlaces() {``            ``pi = 3.14159265359;``            ``twoPlaces = pi.toFixed(2);``            ``fivePlaces = pi.toFixed(5);`` ` `            ``document.querySelector('.output-2').textContent``                    ``= twoPlaces;``            ``document.querySelector('.output-5').textContent``                    ``= fivePlaces;``        ``}``    `````` ` `                    `

Output:

• Before clicking the button:
• After clicking the button:

Using toPrecision() Method: The number of total digits in float values can be set using the toPrecision() method. This method converts the number into a string, keeping the total number of digits of the value as specified and rounding them to the nearest number. If no value is passed as a parameter, then the function acts as a toString() function effectively returning the value passed as a string.

Syntax:

`number.toPrecision(precision)`

Example:

 ```<``html``>``     ` `<``head``>``    ``<``title``>``        ``Floating point number precision``        ``in JavaScript?``    `````` ` `<``body``>``    ``<``h1` `style``=``"color: green"``>``        ``GeeksforGeeks``    ````     ` `    ``<``b``>``        ``Floating point number precision``        ``in JavaScript?``    ````     ` `    ``<``p``>``        ``Original floating point: 3.14159265359``    ````     ` `    ``<``p``>``        ``Floating point when precision set to``        ``2: <``span` `class``=``"output-2"``>``    ````     ` `    ``<``p``>``        ``Floating point when precision set to``        ``5: <``span` `class``=``"output-5"``>``    ```` ` `    ``<``button` `onclick``=``"setPrecision()"``>``        ``Click to check``    ````     ` `    ``<``script` `type``=``"text/javascript"``>``        ``function setPrecision() {``            ``pi = 3.14159265359;``            ``twoPlaces = pi.toPrecision(2);``            ``fivePlaces = pi.toPrecision(5);`` ` `            ``document.querySelector('.output-2').textContent``                    ``= twoPlaces;``            ``document.querySelector('.output-5').textContent``                    ``= fivePlaces;``        ``}``    `````` ` `                    `

Output:

• Before clicking the button:
• After clicking the button:

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