NPM object-assign Package

Object Assign

The object-assign package provides a simple way to copy properties from one or more source objects to a target object. It is a polyfill for the ES6 Object.assign() method, which is not supported in all browsers.

Installation

npm install --save object-assign

Usage

The object-assign() function takes three or more arguments:

• The target object to which properties will be copied.
• One or more source objects from which properties will be copied.

The following example demonstrates how to use the object-assign() function to copy properties from one object to another:

const target = {};
const source = { foo: 1, bar: 2 };

object-assign(target, source);

console.log(target); // { foo: 1, bar: 2 }

The object-assign() function can also be used to copy properties from multiple source objects to a single target object:

const target = {};
const source1 = { foo: 1, bar: 2 };
const source2 = { baz: 3, qux: 4 };

object-assign(target, source1, source2);

console.log(target); // { foo: 1, bar: 2, baz: 3, qux: 4 }

Configuration Options

The object-assign() function does not have any configuration options.

Best Practices

When using the object-assign() function, it is important to be aware of the following best practices:

• The target object must be an object. If the target object is not an object, the function will throw an error.
• The source objects can be of any type. However, it is important to note that the properties of the source objects will be copied to the target object, regardless of their type.
• The object-assign() function will overwrite any existing properties in the target object. If you do not want to overwrite existing properties, you can use the Object.assign() method instead.

Implementation Guide

The object-assign() function is implemented as follows:

function objectAssign(target) {
  if (target === null || target === undefined) {
    throw new TypeError("Cannot convert undefined or null to object");
  }

  for (var i = 1; i < arguments.length; i++) {
    var source = arguments[i];
    if (source !== null && source !== undefined) {
      for (var key in source) {
        if (Object.prototype.hasOwnProperty.call(source, key)) {
          target[key] = source[key];
        }
      }
    }
  }

  return target;
}

Examples

The following examples demonstrate how to use the object-assign() function in different scenarios:

Example 1: Copying properties from one object to another

const target = {};
const source = { foo: 1, bar: 2 };

object-assign(target, source);

console.log(target); // { foo: 1, bar: 2 }

Example 2: Copying properties from multiple source objects to a single target object

const target = {};
const source1 = { foo: 1, bar: 2 };
const source2 = { baz: 3, qux: 4 };

object-assign(target, source1, source2);

console.log(target); // { foo: 1, bar: 2, baz: 3, qux: 4 }

Example 3: Copying properties from an array to an object

const target = {};
const source = [1, 2, 3, 4, 5];

object-assign(target, source);

console.log(target); // { 0: 1, 1: 2, 2: 3, 3: 4, 4: 5 }

Example 4: Copying properties from an object to an array

const target = [];
const source = { foo: 1, bar: 2 };

object-assign(target, source);

console.log(target); // [ { foo: 1, bar: 2 } ]