js 深拷贝

var arr = [1,2,3,4,5]var arr2 = copyArr(arr)function copyArr(arr) { ???let res = [] ???for (let i = 0; i < arr.length; i++) { ????res.push(arr[i]) ???} ???return res}

var arr = [1,2,3]var arr2 = arr.slice(0)arr[2] = 5

var arr = [1,2,3]var arr2 = arr.concat()arr[2] = 5

 ???ES 6var arr = [1,2,3,4,5]var [ ...arr2 ] = arrarr[2] = 5

var obj = { ?name: ‘F‘, ?sex: ‘m‘, ?old: ‘11‘}var obj2 = JSON.parse(JSON.stringify(obj))