去重 函数unique
function unique(arr, key) { if (!arr) return arr if (key === undefined) return [...new Set(arr)] const map = { 'string': e => e[key], 'function': e => key(e), } const fn = map[typeof key] const obj = arr.reduce((o,e) => (o[fn(e)]=e, o), {}) return Object.values(obj)}
一般数组去重
unique([1, 1, 1, 14, 1, 4, 4, 1, 13])
对象数组 去重
const list = [ { id: 0, name: '小明', age: 13 }, { id: 1, name: '小明', age: 99 }, { id: 2, name: '小明', age: 23 }, { id: 3, name: '小红', age: 42 }, { id: 4, name: '小明', age: 13 }, { id: 5, name: '小芳', age: 35 }, { id: 0, name: '小明', age: 13 }, { id: 7, name: '', age: 23 }, { id: 8, name: 'lm', age: 22 }, { id: 9, name: 'xh', age: 79 }]unique(list, 'id') // id 去重unique(list, 'age') // age 去重unique(list, 'name') // name 去重unique(list, e => e.name + e.age) // name+age 去重
实现hashcode 去重
function hashcode(str) { str = typeof str === 'object' ? JSON.stringify(str) : str var hash = 0, i, chr, len; if (str.length === 0) return hash; for (i = 0, len = str.length; i < len; i++) { chr = str.charCodeAt(i); hash = ((hash << 5) - hash) + chr; hash |= 0; // Convert to 32bit integer } return hash;}unique(list, e => hashcode(e)) // hashcode 去重