javascript round only if decimal number code example

Example 1: math.round js 1 decimal

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

Example 2: js round up decimal

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