通过键比较将对象复制到另一个对象

Question

I am trying to copy a object to another by comparing it's key. according to me the key can be nested any of the object node. still I am require to copy them in another object by just comparing their key .

they object key in any level in the object tree.

Is this possible?

here is my try:

var extend = function (original, context, key) {
  for (key in context)
    if (context.hasOwnProperty(key))
      if (Object.prototype.toString.call(context[key]) === '[object Object]')
        original[key] = extend(original[key] || {}, context[key]);
      else
        original[key] = context[key];
  return original;
};

var firstObject = {
    key1 : 'ar',
    key2 : 'value2',
    address:{
    "street" : "D15 Road"
    "sub":{"name":"Stockoverflow"}
    }
};

var secondObject = {
    name:"",
    street:"",
    key3 : 'value3',
    key4 : 'value4'
};
var x = extend(secondObject, firstObject )
console.log( 'extend', x );

In my above try, still the street:"", name:"" not updated.

Answer 1

This should do the trick:

 const source = { key1: 'a', common1: 'value1', a: { b: { c: { common2: 'value2' } } } }; const dest = { key2: 'b', common1: null, common2: null }; function extend(dest, source) { Object.entries(source).forEach(([key, value]) => { if (typeof value === 'object') { extend(dest, value); } else if (dest.hasOwnProperty(key)) { dest[key] = value; } }); } extend(dest, source); console.log(dest); 

Basically, looping through them you only have two options: it's an object or it's key matches.

If it is an object, we just recursively call extend . If it's key matches, then we set the value.

If you want to be able to do this with objects as values (ie, common1 could be an object instead of a primitive), just switch the two in the if statement.