Combine Object Arrays

Introduction

In this lab, we will be working on a JavaScript programming exercise aimed at combining two arrays of objects based on a specified property. The purpose of this exercise is to help you practice using the Array.prototype.reduce() method and object manipulation in JavaScript, which are essential skills for any developer working with JavaScript. By the end of this lab, you should be able to seamlessly combine two arrays of objects based on a property to create a new array.

Skills Graph

%%%%{init: {'theme':'neutral'}}%%%% flowchart RL javascript(("`JavaScript`")) -.-> javascript/BasicConceptsGroup(["`Basic Concepts`"]) javascript(("`JavaScript`")) -.-> javascript/AdvancedConceptsGroup(["`Advanced Concepts`"]) javascript/BasicConceptsGroup -.-> javascript/variables("`Variables`") javascript/BasicConceptsGroup -.-> javascript/data_types("`Data Types`") javascript/BasicConceptsGroup -.-> javascript/arith_ops("`Arithmetic Operators`") javascript/BasicConceptsGroup -.-> javascript/comp_ops("`Comparison Operators`") javascript/BasicConceptsGroup -.-> javascript/cond_stmts("`Conditional Statements`") javascript/BasicConceptsGroup -.-> javascript/array_methods("`Array Methods`") javascript/AdvancedConceptsGroup -.-> javascript/higher_funcs("`Higher-Order Functions`") javascript/AdvancedConceptsGroup -.-> javascript/destr_assign("`Destructuring Assignment`") javascript/AdvancedConceptsGroup -.-> javascript/spread_rest("`Spread and Rest Operators`") subgraph Lab Skills javascript/variables -.-> lab-28201{{"`Combine Object Arrays`"}} javascript/data_types -.-> lab-28201{{"`Combine Object Arrays`"}} javascript/arith_ops -.-> lab-28201{{"`Combine Object Arrays`"}} javascript/comp_ops -.-> lab-28201{{"`Combine Object Arrays`"}} javascript/cond_stmts -.-> lab-28201{{"`Combine Object Arrays`"}} javascript/array_methods -.-> lab-28201{{"`Combine Object Arrays`"}} javascript/higher_funcs -.-> lab-28201{{"`Combine Object Arrays`"}} javascript/destr_assign -.-> lab-28201{{"`Combine Object Arrays`"}} javascript/spread_rest -.-> lab-28201{{"`Combine Object Arrays`"}} end

Function to Combine Object Arrays Based on a Specified Key

To combine two arrays of objects based on a specific key, follow these steps:

Open the Terminal/SSH and type node to start practicing coding.
Use Array.prototype.reduce() with an object accumulator to combine all objects in both arrays based on the given prop.
Use Object.values() to convert the resulting object to an array and return it.

Here's the function that you can use:

const combine = (a, b, prop) =>
  Object.values(
    [...a, ...b].reduce((acc, v) => {
      if (v[prop])
        acc[v[prop]] = acc[v[prop]] ? { ...acc[v[prop]], ...v } : { ...v };
      return acc;
    }, {})
  );

Here's an example of how to use this function:

const x = [
  { id: 1, name: "John" },
  { id: 2, name: "Maria" }
];
const y = [{ id: 1, age: 28 }, { id: 3, age: 26 }, { age: 3 }];
combine(x, y, "id");
// [
//  { id: 1, name: 'John', age: 28 },
//  { id: 2, name: 'Maria' },
//  { id: 3, age: 26 }
// ]

Summary

Congratulations! You have completed the Combine Object Arrays lab. You can practice more labs in LabEx to improve your skills.

Combine Object Arrays

Introduction

Skills Graph

Function to Combine Object Arrays Based on a Specified Key

Summary

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