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I'm using a generator to create objects, like so:

function* Thing() {
  var x = 0;
  while (x < 3) {
    var rules = [{arr: [1, 2, 3]}, {arr: [1]}, {arr: []}];
    yield {
      arrayMinimum: Math.min(...rules[x].arr)
    }
    x++
  }
}

var create = Thing();

console.log(create.next().value)
console.log(create.next().value)
console.log(create.next().value) // { arrayMinimum: Infinity } ???

I'm using a generator to create objects, like so:

function* Thing() {
  var x = 0;
  while (x < 3) {
    var rules = [{arr: [1, 2, 3]}, {arr: [1]}, {arr: []}];
    yield {
      arrayMinimum: Math.min(...rules[x].arr)
    }
    x++
  }
}

var create = Thing();

console.log(create.next().value)
console.log(create.next().value)
console.log(create.next().value) // { arrayMinimum: Infinity } ???

Why is Math.min(...[]) === Infinity?

Bonus confusion: Math.max(...[]) === -Infinity ???

  • javascript
  • arrays
  • ecmascript-6
Share Improve this question edited Mar 27, 2017 at 18:42 Kris Molinari asked Mar 27, 2017 at 18:26 Kris MolinariKris Molinari 5036 silver badges17 bronze badges 1
  • ... is not an operator! (didn't even know we had a tag for that :( ) – Felix Kling Commented Mar 27, 2017 at 18:40
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1 Answer 1

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This is because the arguments-list specified by (...[]) is the empty list of arguments -- i.e., you are doing Math.min() with no arguments.

The EMCAScript spec for Math.min states:

If no arguments are given, the result is +∞.

(And, unsurprisingly, it has a similar statement for Math.max.)

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