round to nearest decimal javascript

1var number = 12.3456789;
2var rounded = Math.round( number * 10 ) / 10;
3// rounded is 12.3

1let num = 12.5452411;
2num = num.toFixed(3); // 12.545

1round(12345.6789, 2) // 12345.68
2round(12345.6789, 1) // 12345.7

1round(456.7, 2).toFixed(2) // "456.70"

1function round(value, precision) {
2    var multiplier = Math.pow(10, precision || 0);
3    return Math.round(value * multiplier) / multiplier;
4}

1round(12345.6789, -1) // 12350
2round(12345.6789, -2) // 12300