SOURCE

function deepClone(target) {
    if(target === null || typeof target !== 'object') {
        return target;
    }
    let obj = Array.isArray(target) ? [] : {};
    
    for(let key in target) {
        if(target.hasOwnProperty(key)) {
            obj[key] = deepClone(target[key]);
        }
    }
    return obj;
}
let data = {
    name: 'wx',
    age: 18,
    six: null,
    child: {
        name: 'ww'
    }
}
console.log(deepClone(data))