javascript round down to 1 decimal code example

Example 1: js round up decimal

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

Example 2: javascript round .5 down

//standard round function, except round .5 down instead of up
function roundHalfDown(num) {
  return -Math.round(-num);
}
roundHalfDown(1.5);// 1
roundHalfDown(1.6);// 2