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