Finds index of leftmost value passing a test. :running: :vhs: :package: :moon: :ledger:

Alternatives: findIndex, findIndices. Similar: find, findIndex. This is part of package extra-array.

array.findIndex(x, fn);
// x:  an array
// fn: test function (v, i, x)
// --> index of value, -1 if not found

const array = require('extra-array');

var x = [1, 2, 3, 4, 5];
array.findIndex(x, v => v % 2 == 0);
// 1        ^

array.findIndex(x, v => v % 2 == 1);
// 0     ^

references

• Data.List.findIndex: Haskell
• List-Extra.findIndex: elm
• _.findIndex: lodash
• Array.findIndex: sugarjs