56 lines
1.4 KiB
JavaScript
56 lines
1.4 KiB
JavaScript
var baseFindIndex = require('./_baseFindIndex'),
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baseIsNaN = require('./_baseIsNaN'),
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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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nativeMin = Math.min;
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/**
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* This method is like `_.indexOf` except that it iterates over elements of
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* `array` from right to left.
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*
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* @static
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* @memberOf _
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* @since 0.1.0
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* @category Array
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* @param {Array} array The array to inspect.
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* @param {*} value The value to search for.
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* @param {number} [fromIndex=array.length-1] The index to search from.
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* @returns {number} Returns the index of the matched value, else `-1`.
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* @example
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*
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* _.lastIndexOf([1, 2, 1, 2], 2);
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* // => 3
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*
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* // Search from the `fromIndex`.
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* _.lastIndexOf([1, 2, 1, 2], 2, 2);
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* // => 1
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*/
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function lastIndexOf(array, value, fromIndex) {
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var length = array ? array.length : 0;
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if (!length) {
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return -1;
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}
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var index = length;
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if (fromIndex !== undefined) {
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index = toInteger(fromIndex);
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index = (
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index < 0
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? nativeMax(length + index, 0)
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: nativeMin(index, length - 1)
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) + 1;
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}
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if (value !== value) {
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return baseFindIndex(array, baseIsNaN, index - 1, true);
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}
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while (index--) {
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if (array[index] === value) {
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return index;
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}
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}
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return -1;
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}
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module.exports = lastIndexOf;
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