Intersect and merge two array of objects

Question

I have two arrays:

var odd = [
    { name : "1", extraProp1 : "propValue1" },
    { name : "3",  extraProp1 : "propValue2"         


        

Answer 1

The most efficient way I can see (although maybe not leveraging JS predefined functions) is making up a dictionary with the name values as the keys.

You can go through the first array and populate the dictionary. Then you can iterate through the second array and add each element to the dictionary if it doesn't contain the name or merge the objects if it does.

Example:

var odd = [
    { name : "1", extraProp1 : "propValue1" },
    { name : "3",  extraProp1 : "propValue2"}
];

var even = [
    { name : "1", extraProp2 : "prop1" },
    { name : "2", extraProp2 : "prop2"},
    { name : "4", extraProp2 : "prop3" }
]; 

var combinedDictionary = {}

for(let obj of odd) {
  combinedDictionary[obj.name] = obj;
}

for(let obj of even) {
  combinedDictionary[obj.name] = { 
    ...(combinedDictionary[obj.name] || {}),
    ...obj
  };
}

var result = Object.keys(combinedDictionary).map(key => combinedDictionary[key]);

console.log(result);