toPrecision() returns a string, with a number written with a specified length: code example

Example: toPrecision() returns a string, with a number written with a specified length:

var x = 9.656;

x.toPrecision();        // returns 9.656

x.toPrecision(2);       // returns 9.7

x.toPrecision(4);       // returns 9.656

x.toPrecision(6);       // returns 9.65600