在nodeschool上看到這個(gè)問題function countWords(arr) { return arr.reduce(function(countMap, word) {
countMap[word] = ++countMap[word] || 1 // increment or initialize to 1
return countMap
}, {}) // second argument to reduce initialises countMap to {}}module.exports = countWords傳入數(shù)據(jù)var inputWords = ['Apple', 'Banana', 'Apple', 'Durian', 'Durian', 'Durian']得到的結(jié)果{ // Apple: 2,
// Banana: 1,
// Durian: 3
// }實(shí)現(xiàn)這個(gè)過程的js原理是什么
reduce統(tǒng)計(jì)個(gè)數(shù)問題
開滿天機(jī)
2018-09-15 10:09:29