42 lines
1.2 KiB
JavaScript
42 lines
1.2 KiB
JavaScript
var baseIndexOf = require('./_baseIndexOf'),
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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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* Gets the index at which the first occurrence of `value` is found in `array`
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* using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero)
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* for equality comparisons. If `fromIndex` is negative, it's used as the
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* offset from the end of `array`.
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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=0] 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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* _.indexOf([1, 2, 1, 2], 2);
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* // => 1
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*
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* // Search from the `fromIndex`.
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* _.indexOf([1, 2, 1, 2], 2, 2);
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* // => 3
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*/
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function indexOf(array, value, 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 baseIndexOf(array, value, index);
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}
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module.exports = indexOf;
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