两个数组去重,或取相同元素

     //去重a1 = ["id","name","url"] a2=["id","name"]getArrDifference(a1, a2) {return a1.concat(a2).filter(function (v, i, arr) {return arr.indexOf(v) === arr.lastIndexOf(v);});},console.log(this.getArrDifference(a1,a2))  //["url"]//取相同元素let a3 = [];for(let i of a1) {for(let j of a2) {if(i===j) {a3.push(i)}}}