round number js code example

Example 1: how to displayan inteiger to a tenth in javascript

Math.round(3.14159 * 100) / 100  // 3.14

3.14159.toFixed(2);              // 3.14 returns a string
parseFloat(3.14159.toFixed(2));  // 3.14 returns a number

Math.round(3.14159)  // 3
Math.round(3.5)      // 4
Math.floor(3.8)      // 3
Math.ceil(3.2)       // 4

Example 2: javascript round to 2 decimal places

var subTotal="12.1345";// can also be int, float, string
var subTotalFormatted=parseFloat(subTotal).toFixed(2); //"12.13"

Example 3: js rounding

//There are meny ways of rounding...
Math.floor(5.5) //Answer 5, it alwas rounds down.
Math.round(5.5) //Answer 6, it simpily rounds to the closest whole number.
Math.ceil(5.5) //Answer 6, it alwas rounds up.

//You can do more things too...
Math.floor(5.57 * 10) / 10 //Answer 5.5, the number turns into 55.7, Then gets floored (55.0), Then gets divied, (5.5).

Example 4: rounding off in javascript

var avg=10.55;
console.log(Math.round(avg)); //Prints 11

Example 5: rounding off numbers javascript

Math.round(3.14159 * 100) / 100  // 3.14

3.14159.toFixed(2);              // 3.14 returns a string
parseFloat(3.14159.toFixed(2));  // 3.14 returns a number

Example 6: javascript round

function round(num, places) {
    num = parseFloat(num);
    places = (places ? parseInt(places, 10) : 0)
    if (places > 0) {
        let length = places;
        places = "1";
        for (let i = 0; i < length; i++) {
            places += "0";
            places = parseInt(places, 10);
        }
    } else {
        places = 1;
    }
    return Math.round((num + Number.EPSILON) * (1 * places)) / (1 * places)
}

round(1.005, 2); // 1.01
round(1.005, "1"); // 1
round("1.23", 1); // 1.2
round("1.436", "2"); // 1.44