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Lodash _.merge

Overview

The lodash library provides a utility method called _.merge which is used to deeply merge two or more plain object arguments. The method combines the properties of the source object(s) into the destination object recursively. If the same property exists in both the source and destination objects, then the value from the source object overrides the value in the destination object.

The syntax of the _.merge method is as follows:

_.merge(object, [sources])

where object is the destination object and sources are the source object(s) to merge into the destination object.

The _.merge method returns the modified destination object.

The _.merge method can be used to merge properties of multiple objects into a single object. This method is particularly useful when dealing with configuration options or merging different data sources.

Here is an example of using the _.merge method:

const object1 = {
  a: [{ b: 2 }, { d: 4 }]
};
 
const object2 = {
  a: [{ c: 3 }, { e: 5 }]
};
 
_.merge(object1, object2);
 
// Output: { a: [{ b: 2, c: 3 }, { d: 4, e: 5 }] }

In the above example, we have two objects object1 and object2. Both objects have the same property a which is an array of objects. When we pass these objects to the _.merge method, it combines the properties of the a arrays into a single array. The resulting object has only one property a which contains the merged array.

It is important to note that _.merge only merges plain objects. It does not merge functions or non-enumerable properties.

In conclusion, the _.merge method is a powerful utility method in the lodash library that can be used to deeply merge two or more objects. It is a useful tool for merging configuration options or data from multiple sources.