Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Math.min(Math.max(num, min), max)

twitter.com

Post reply on HN
Print view View original

1–10 of 291 posts

Re: Math.min(Math.max(num, min), max)

#2

Post by STRML »

The basic function is simply defined as:

  function clamp(num, min, max) {
    return Math.max(min, Math.min(num, max));
  }
That is, if you don't try to do anything fancy and make any parameters optional. Lodash does and it makes the implementation much more complex.

  _.clamp(input: number, lower?: number, upper: number): number;
https://github.com/lodash/lodash/blob/ddfd9b11a0126db2302cb7...

Re: Math.min(Math.max(num, min), max)

#3

Post by [deleted] »

STRML wrote: post #2

The basic function is simply defined as: function clamp(num, min, max) { return Math.max(min, Math.min(num, max)); } That is, if you don't try to do anything fancy and make any parameters optional. Lodash does and it makes the implementation much more complex. _.clamp(input: number, lower?: number, upper: number): number; https://github.com/lodash/lodash/blob/ddfd9b11a0126db2302cb7...

[deleted]

Re: Math.min(Math.max(num, min), max)

#4

Post by css »

Very coincidental I see this post almost immediately after writing the same code:

    new_poll_rate = \
        min(
            max(
                1 / messages_per_second,
                constants.FASTEST_POLL_RATE
            ),
            constants.SLOWEST_POLL_RATE
        )
I agree with the sentiment, I had to re-read this several times to make sure I got it right.

Re: Math.min(Math.max(num, min), max)

#5

Post by bonoboTP »

STRML wrote: post #2

The basic function is simply defined as: function clamp(num, min, max) { return Math.max(min, Math.min(num, max)); } That is, if you don't try to do anything fancy and make any parameters optional. Lodash does and it makes the implementation much more complex. _.clamp(input: number, lower?: number, upper: number): number; https://github.com/lodash/lodash/blob/ddfd9b11a0126db2302cb7...

Or to make sure it's crystal clear what's going on:

    function clamp(num, min, max) {
      if (num > max)
        return max;
      if (num

Re: Math.min(Math.max(num, min), max)

#6

Post by ebg13 »

> it takes me ages to convince myself this implementation is correct

It would take them less time to convince themself if they switched min and num to put the values in proper semantic order: min Math.min(Math.max(min, num), max)

Re: Math.min(Math.max(num, min), max)

#7

Post by rewq4321 »

Stage 1 ECMAScript proposal to add Math.clamp (among others): https://github.com/rwaldron/proposal-math-extensions

But it looks dead: https://github.com/rwaldron/proposal-math-extensions/issues/...

As someone mentioned in the thread, nested ternary is easier to interpret:

(a > max ? max : (a < min ? min : a))

Re: Math.min(Math.max(num, min), max)

#8

Post by matthewmacleod »

bonoboTP wrote: post #5
STRML wrote: post #2

The basic function is simply defined as: function clamp(num, min, max) { return Math.max(min, Math.min(num, max)); } That is, if you don't try to do anything fancy and make any parameters optional. Lodash does and it makes the implementation much more complex. _.clamp(input: number, lower?: number, upper: number): number; https://github.com/lodash/lodash/blob/ddfd9b11a0126db2302cb7...

Or to make sure it's crystal clear what's going on: function clamp(num, min, max) { if (num > max) return max; if (num

Seriously. This is about a million times better.

Re: Math.min(Math.max(num, min), max)

#9

Post by jaffathecake »

bonoboTP wrote: post #5
STRML wrote: post #2

The basic function is simply defined as: function clamp(num, min, max) { return Math.max(min, Math.min(num, max)); } That is, if you don't try to do anything fancy and make any parameters optional. Lodash does and it makes the implementation much more complex. _.clamp(input: number, lower?: number, upper: number): number; https://github.com/lodash/lodash/blob/ddfd9b11a0126db2302cb7...

Or to make sure it's crystal clear what's going on: function clamp(num, min, max) { if (num > max) return max; if (num

Yep, I came to the same conclusion https://twitter.com/jaffathecake/status/1296423819238944768

Re: Math.min(Math.max(num, min), max)

#10

Post by jaffathecake »

ebg13 wrote: post #6

> it takes me ages to convince myself this implementation is correct It would take them less time to convince themself if they switched min and num to put the values in proper semantic order: min Math.min(Math.max(min, num), max)

I don't think so. Whereas an if statement is easy to read https://twitter.com/jaffathecake/status/1296423819238944768
Post reply on HN