Function findFirstIndex

Find the index of the first value which matches a predicate.

Returns

The index of the first matching value, or -1 if no matching value is found.

Notes

If stop < start the search will wrap at the end of the array.

Complexity

Linear.

Undefined Behavior

A start or stop which is non-integral.

Modifying the length of the array while searching.

Example

import { ArrayExt } from '@lumino/algorithm';

function isEven(value: number): boolean {
  return value % 2 === 0;
}

let data = [1, 2, 3, 4, 3, 2, 1];
ArrayExt.findFirstIndex(data, isEven);       // 1
ArrayExt.findFirstIndex(data, isEven, 4);    // 5
ArrayExt.findFirstIndex(data, isEven, 6);    // -1
ArrayExt.findFirstIndex(data, isEven, 6, 5); // 1