@extra-array/find-indices/index.js

Finds indices of values passing a test.

'use strict';

/**
 * Finds indices of values passing a test.
 * @param x an array
 * @param ft test function (v, i, x)
 */
function findIndices(x, ft) {
    var a = [], i = -1;
    for (var v of x)
        if (ft(v, ++i, x))
            a.push(i);
    return a;
}

module.exports = findIndices;