在javascript中获取小数点后的值

Question

I have a javascript number 12.1542. and I want the new string 12.(1542*60) from this string.

How can I get it. Thanks

Answer 1

You could use the modulus operator :

var num = 12.1542;
console.log(num % 1);

However, due to the nature of floating point numbers, you will get a number that is very slightly different. For the above example, Chrome gives me 0.15419999999999945 .

Another (slightly longer) option would be to use Math.floor and then subtract the result from the original number:

var num = 12.1542;
console.log(num - Math.floor(num));​

Again, due to the nature of floating point numbers you will end up with a number that is very slightly different than you may expect.

Answer 2

floor is probably the method to get what you want:

http://www.w3schools.com/jsref/jsref_floor.asp

You could also use ceil

http://www.w3schools.com/jsref/jsref_obj_math.asp

Answer 3

Input sanity checks aside, this should work:

var str = '12.1542';
var value = Math.floor( str ) + ( 60 * (str - Math.floor( str ) ) );

Answer 4

Time to decimals:

function toDec(sec){
    var itg=Math.floor(sec);
    sec=(sec-itg)*60;
    return itg+sec; // OR: return new String(itg+sec);
}

Answer 5

let Decimal = "12.56"

Decimal.substring(Decimal.indexOf(".")+1, Decimal .length)

// answer is 56.