var baseFindIndex = require('./_baseFindIndex'), baseIteratee = require('./_baseIteratee'), toInteger = require('./toInteger'); /* Built-in method references for those with the same name as other `lodash` methods. */ var nativeMax = Math.max; /** * This method is like `_.find` except that it returns the index of the first * element `predicate` returns truthy for instead of the element itself. * * @static * @memberOf _ * @since 1.1.0 * @category Array * @param {Array} array The array to inspect. * @param {Function} [predicate=_.identity] * The function invoked per iteration. * @param {number} [fromIndex=0] The index to search from. * @returns {number} Returns the index of the found element, else `-1`. * @example * * var users = [ * { 'user': 'barney', 'active': false }, * { 'user': 'fred', 'active': false }, * { 'user': 'pebbles', 'active': true } * ]; * * _.findIndex(users, function(o) { return o.user == 'barney'; }); * // => 0 * * // The `_.matches` iteratee shorthand. * _.findIndex(users, { 'user': 'fred', 'active': false }); * // => 1 * * // The `_.matchesProperty` iteratee shorthand. * _.findIndex(users, ['active', false]); * // => 0 * * // The `_.property` iteratee shorthand. * _.findIndex(users, 'active'); * // => 2 */ function findIndex(array, predicate, fromIndex) { var length = array ? array.length : 0; if (!length) { return -1; } var index = fromIndex == null ? 0 : toInteger(fromIndex); if (index < 0) { index = nativeMax(length + index, 0); } return baseFindIndex(array, baseIteratee(predicate, 3), index); } module.exports = findIndex;