前端 数组 对象 交 并 补
数组 交并补
var a=[1,2,3,5,7,8,9] var b=[5,4,6,34,6,8,7] // 交 a.filter(item=>b.includes(item)) // 并 [...new Set(a.connect(b))] // 补 a.filter(item=>!b.includes(item))
对象 交并补
var a=[ {id:'001',name:'zhangsan'}, {id:'002',name:'tom'}, {id:'003',name:'jack'}, {id:'004',name:'fei'}, {id:'005',name:'ming'} ]; var b=[ {id:'003',name:'jack'}, {id:'005',name:'ming'}, {id:'007',name:'hello'}, {id:'008',name:'milk'}, ]; var obj={}; var arr=a.concat(b); // 交集:定义一个对象,通过其属性值是否出现多次判断交集 arr.reduce(function(pre,cur){ obj.hasOwnProperty(cur.id)?pre.push(cur):obj[cur.id]=true; return pre; },[]); // 并集:每次遍历将还未出现的项进行收集 arr.reduce(function(pre,cur){ if(!obj.hasOwnProperty(cur.id)){ pre.push(cur); } obj[cur.id]=true; return pre; },[]) //补集:a中每一项都不在b中 let test=a.reduce(function(pre,cur){ if(b.every(item=>item.id!==cur.id)){ pre.push(cur) } return pre; },[])