SOURCE

function deepCopy(target){
    let obj = null;
    if(typeof target === 'object'&&target!=='null'){
        obj = target instanceof Array?[]:{};
        for(let i in target){
            obj[i] = deepCopy(target[i]);
        }
    }else{
        obj = target;
    }
    return obj;
}

let arr = [
    {name: '张三', age: 23, sex: '男', flag: false, obj: {student: '小学'}},
    {name: 'lisi', age: 17, sex: '女', flag: true, arr: [{room: "123"}]},
    {name: 'wang', age: 35, sex: '男', flag: false},
]
console.log(arr);
let copyArr = deepCopy(arr);
console.log(copyArr);
copyArr[0].name = 'zhangsan';
console.log(copyArr);