round down javascript code example

Example 1: javascript round down

Math.floor(x);

Example 2: round up javascript

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

Example 3: round down the number javascript

+3.5 => +3.0
-3.5 => -4.0

+3.5 => +3.0 using Math.floor()
-3.5 => -3.0 using Math.ceil()

Example 4: javascript floor

Math.floor(1.6);

result: 1

Example 5: 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