11 lines
286 B
JavaScript
11 lines
286 B
JavaScript
'use strict';
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module.exports = function countBy() {
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var fn = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : function (value) {
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return value;
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};
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return new this.constructor(this.items).groupBy(fn).map(function (value) {
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return value.count();
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});
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}; |