JS toPrecision Function

toPrecision() function formats a number with specified digits.

alert(Math.PI); //3.141592653589793
Math.PI.toPrecision(5); //3.14159

toPrecision()function is different from toFixed(), as the precision digits include digits at the left of the point.

alert(Math.PI); //3.141592653589793
Math.PI.toFixed(5); //3.1415

var nm = 436.32943;
alert(nm.toPrecision(5)); //436.33