7 ms·

[‘1’,’2’,’3’,’4’,’5’,’6’,’7’,’8’,’9’,’10’].map(d => parseInt(d)); Returns [1,2,3,4,5,6,7,8,9,10]

inferiorhuman 8y ago
I'd expect your example to return a syntax error as those aren't single or double quotes. Try: ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10"].map(parseInt);
- duckerude 8y ago
  Backticks are used for template literals. Try evaluating `2 + 2 = ${2 + 2}`.
  - inferiorhuman 8y ago
    Those weren't backticks (`) either. They were "smart" quotes (’ -- you may need a different font to view the differences more readily ’ vs ').
    - rounce 8y ago
      But you understood what they meant right?
JimDabell 8y ago
Sure, but you're putting a workaround in – there really shouldn't be any need for that no-op arrow function. But you do actually need it in order to drop all but the first arguments. This is simple, straightforward, and wrong: ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10"].map(parseInt) This doesn't work because map() stuffs a counter into the second argument of parseInt(), which is expecting a radix for its second argument. So the iterations of the map go like this: parseInt("1", 0) parseInt("2", 1) parseInt("3", 2) …and so on, which obviously gives garbage results. JavaScript is littered with these kinds of weird edge cases. Even your example with the workaround isn't 100% reliable, it's browser-dependent – when you have leading zeros in your strings, some browsers will interpret them as octal, and some won't.
- gear54rus 8y ago
  so what is your problem with all this? that these functions have both provided a flexible interface for use cases that are not this single one?
- kybernetikos 8y ago
  > browser-dependent Language version dependent rather than browser dependent. It may seem the same (after all, different browsers implement different versions of the language), but it's a bit different, if you say 'browser-dependent' it makes it sound like there is no standard when in fact, the leading zero behaviour hasn't been the case since ecmascript 5. You'll struggle to find a browser in common use that doesn't support at least ecmascript 5. It's as browser-dependent as the array.map function which was added at the same time. Your example code would never have the leading 0 problem since you're using array.map and array.map didn't exist in the engines that had that leading 0 'feature'.

I'd expect your example to return a syntax error as those aren't single or double quotes. Try: ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10"].map(parseInt);

duckerude 8y ago
Backticks are used for template literals. Try evaluating `2 + 2 = ${2 + 2}`.
- inferiorhuman 8y ago
  Those weren't backticks (`) either. They were "smart" quotes (’ -- you may need a different font to view the differences more readily ’ vs ').
  - rounce 8y ago
    But you understood what they meant right?

JimDabell 8y ago

Sure, but you're putting a workaround in – there really shouldn't be any need for that no-op arrow function. But you do actually need it in order to drop all but the first arguments. This is simple, straightforward, and wrong: ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10"].map(parseInt) This doesn't work because map() stuffs a counter into the second argument of parseInt(), which is expecting a radix for its second argument. So the iterations of the map go like this: parseInt("1", 0) parseInt("2", 1) parseInt("3", 2) …and so on, which obviously gives garbage results. JavaScript is littered with these kinds of weird edge cases. Even your example with the workaround isn't 100% reliable, it's browser-dependent – when you have leading zeros in your strings, some browsers will interpret them as octal, and some won't.

gear54rus 8y ago
so what is your problem with all this? that these functions have both provided a flexible interface for use cases that are not this single one?
kybernetikos 8y ago
> browser-dependent Language version dependent rather than browser dependent. It may seem the same (after all, different browsers implement different versions of the language), but it's a bit different, if you say 'browser-dependent' it makes it sound like there is no standard when in fact, the leading zero behaviour hasn't been the case since ecmascript 5. You'll struggle to find a browser in common use that doesn't support at least ecmascript 5. It's as browser-dependent as the array.map function which was added at the same time. Your example code would never have the leading 0 problem since you're using array.map and array.map didn't exist in the engines that had that leading 0 'feature'.