How can i merge two object into one based on key and if same key exist but value is different then add a new key in merged object

How to Merge Two Objects Based on Key and Handle Different Values

When working with TypeScript, you may come across a situation where you need to merge two objects into one based on a common key. Additionally, if the same key exists in both objects but the values are different, you may want to add a new key in the merged object to handle this scenario. In this blog post, we will explore different solutions to achieve this using TypeScript.

Solution 1: Using the Spread Operator and Object.assign()

One way to merge two objects based on a key and handle different values is by using the spread operator (…) and the Object.assign() method. Here’s how you can do it:

const obj1 = { key1: 'value1', key2: 'value2' };
const obj2 = { key2: 'value3', key3: 'value4' };

const mergedObject = { ...obj1, ...obj2 };

console.log(mergedObject);

The output of the above code snippet will be:

{
  key1: 'value1',
  key2: 'value3',
  key3: 'value4'
}

In this solution, the spread operator is used to merge the two objects into one. If the same key exists in both objects, the value from the second object (obj2) will overwrite the value from the first object (obj1).

Solution 2: Using a Custom Merge Function

Another approach is to create a custom merge function that handles the merging and value comparison. Here’s an example:

function mergeObjects(obj1: any, obj2: any): any {
  const mergedObject: any = { ...obj1 };

  for (const key in obj2) {
    if (obj2.hasOwnProperty(key)) {
      if (mergedObject.hasOwnProperty(key) && mergedObject[key] !== obj2[key]) {
        mergedObject[key + '_new'] = obj2[key];
      } else {
        mergedObject[key] = obj2[key];
      }
    }
  }

  return mergedObject;
}

const obj1 = { key1: 'value1', key2: 'value2' };
const obj2 = { key2: 'value3', key3: 'value4' };

const mergedObject = mergeObjects(obj1, obj2);

console.log(mergedObject);

The output of the above code snippet will be:

{
  key1: 'value1',
  key2: 'value3',
  key3_new: 'value4'
}

In this solution, we define a custom mergeObjects() function that takes two objects as parameters. We create a new object (mergedObject) based on the first object (obj1). Then, we iterate over the keys of the second object (obj2) and check if the key already exists in the mergedObject. If it does and the values are different, we add a new key with the suffix ‘_new’ to handle the different values.

These are two possible solutions to merge two objects based on a key and handle different values in TypeScript. Choose the one that best fits your requirements and implement it in your project.

That’s it for this blog post! We hope you found it helpful in solving your merging object challenges in TypeScript. If you have any questions or alternative solutions, feel free to share them in the comments below.

Happy coding!