Javascript: How to use map and filter between two array object

April 6, 2022

I am facing some issue on using .map and .filter where I am unable to get the object which is not similar in two objects.
What changes I need to do to get the uncommon object from arrayObjTwo.

code

const arrayObjOne = [{
          countryCode: "US",
          description: " Backyard of home",
          id: "1234",
          location: "US",
          name: "Backyard",
          }]
// Array Object 2
const arrayObjTwo =[
    { description: "Backyard of home", spaceName: "Backyard" },
    { description: "Frontyard of home", spaceName: "Frontyard"},
]
const object1Names = arrayObjOne.map(obj => obj.Name); // for caching the result
const results = arrayObjTwo.filter(name => !object1Names.includes(name));
console.log(results);

One compiler code: https://onecompiler.com/javascript/3xy92hpmp

expected result:

const arrayObjTwo =[
        { description: "Frontyard of home", spaceName: "Frontyard" }
    ]

Thanks..

>Solution :

Your filter for the result is wrong. You should be using the "object.spaceName" instead of just "name" as you’re looping through an array of objects and not just strings

// So this line:
const results = arrayObjTwo.filter(name => !object1Names.includes(name));

// Should be:
const results = arrayObjTwo.filter(object => !object1Names.includes(object.spaceName));

// And you have a typo:
const object1Names = arrayObjOne.map(obj => obj.Name);

// Should be like so as keys and properties are case-sensitive:
const object1Names = arrayObjOne.map(obj => obj.name);

So this should all be:

const arrayObjOne = [{
          countryCode: "US",
          description: " Backyard of home",
          id: "1234",
          location: "US",
          name: "Backyard",
          }]
// Array Object 2
const arrayObjTwo =[
    { description: "Backyard of home", spaceName: "Backyard" },
    { description: "Frontyard of home", spaceName: "Frontyard"},
]
const object1Names = arrayObjOne.map(obj => obj.name); // for caching the result
const results = arrayObjTwo.filter(object => !object1Names.includes(object.spaceName));
console.log(results);