Tuesday, 7 May, 2019 UTC


JavaScript’s loose nature allows developers to employ amazing tricks to do just about anything you’d like. I’ve detailed how you can filter falsy values in arrays using a filter(Boolean) trick, but reader David Hibshman shared another trick for typecasting array values the same way.
To typecast an array of elements, you can use map and the desired return type:
["1", "9", "-9", "0.003", "yes"].map(Number);
// [1, 9, -9, 0.003, NaN]
I love this trick but you could argue the code itself could be considered confusing, so wrapping it a helper function would be helpful:
function arrToNumber(arr) {
  return arr.map(Number).filter(Boolean);
Validation could and should probably be more rigorous but basic validation through typecasting might help you!
The post Type Conversion with JavaScript Arrays appeared first on David Walsh Blog.