Javascript Math Object Methods - negatives to zero

Question

in Javascript I can't seem to find a method to set negatives to zero?

-90 becomes 0
-45 becomes 0
0 becomes 0
90 becomes 90

Is there anything like that? I have just rounded numbers.

Solution 1

Just do something like

value = value < 0 ? 0 : value;

or

if (value < 0) value = 0;

or

value = Math.max(0, value);

Solution 2

I suppose you could use Math.max().

var num = 90;
num = Math.max(0,num) || 0; // 90

var num = -90;
num = Math.max(0,num) || 0; // 0

Solution 3

If you want to be clever:

num = (num + Math.abs(num)) / 2;

However, Math.max or a conditional operator would be much more understandable.
Also, this has precision issues for large numbers.

Solution 4

Math.positive = function(num) {
  return Math.max(0, num);
}

// or 

Math.positive = function(num) {
  return num < 0 ? 0 : num;
}

Solution 5

x < 0 ? 0 : x does the job .

View more solutions

Comments

[Skeep]

Quick JSPerf shows value = value < 0 ? 0 : value; is on top jsperf.com/negatives-to-zero

[ksugiarto]

This one should be the accepted answer in my opinion. Just saying... :)

[Matt Fletcher]

I like the Math.max one the most, because it only requires referencing value once

[Killy]

zero is neither positive nor negative, your function should be renamed according to that

[jwerre]

One thing to keep in mind is that both Math.max(0, NaN) and Math.max(0, undefined) return NaN so you may want to do something along these lines: Math.max(0, num) || 0

[insign]

In a more fair benchmark, Math.max wins probably because it was already instantiated once. jsbench.me/tbkmm8varf/1

[squarecandy]

@insign - I'm getting different results every time I run your benchmark - sometimes a 3 way tie. Seems like readability and consistency are more important factors if the margins are so close between them.

[RedGuy11]

What's the ~~?

[kungfooman]

@RedGuy11 The ~~ is obstrusive and wrong, it converts it to binary. Which in turn makes it work ONLY for integers: ~~.1 == 0 Not sure why this is upvoted so often, no one sees how wrong it is?