22 lines
973 B
JavaScript
22 lines
973 B
JavaScript
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'use strict';
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var $export = require('./_export')
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, toIObject = require('./_to-iobject')
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, toInteger = require('./_to-integer')
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, toLength = require('./_to-length')
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, $native = [].lastIndexOf
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, NEGATIVE_ZERO = !!$native && 1 / [1].lastIndexOf(1, -0) < 0;
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$export($export.P + $export.F * (NEGATIVE_ZERO || !require('./_strict-method')($native)), 'Array', {
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// 22.1.3.14 / 15.4.4.15 Array.prototype.lastIndexOf(searchElement [, fromIndex])
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lastIndexOf: function lastIndexOf(searchElement /*, fromIndex = @[*-1] */){
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// convert -0 to +0
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if(NEGATIVE_ZERO)return $native.apply(this, arguments) || 0;
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var O = toIObject(this)
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, length = toLength(O.length)
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, index = length - 1;
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if(arguments.length > 1)index = Math.min(index, toInteger(arguments[1]));
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if(index < 0)index = length + index;
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for(;index >= 0; index--)if(index in O)if(O[index] === searchElement)return index || 0;
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return -1;
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}
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});
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