22 lines
510 B
JavaScript
22 lines
510 B
JavaScript
var groupBy = require('./groupBy')
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var objectEach = require('./objectEach')
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/**
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* 集合分组统计,返回各组中对象的数量统计
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*
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* @param {Array} obj 对象
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* @param {Function} iterate 回调/对象属性
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* @param {Object} context 上下文
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* @return {Object}
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*/
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function countBy (obj, iterate, context) {
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var result = groupBy(obj, iterate, context || this)
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objectEach(result, function (item, key) {
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result[key] = item.length
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})
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return result
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}
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module.exports = countBy
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