How to Define the Array.prototype.toString() Method in JavaScript?

The Array.prototype.toString() method in JavaScript returns a string representing the elements of an array. By default, this method joins the elements of the array with commas and returns a string. However, you can define your own implementation of the toString() method for an array using the Array.prototype.toString() method.

To define the Array.prototype.toString() method, you can add a new function to the Array.prototype object. This function will be called when the toString() method is called on an array. Here’s an example of how you can define the toString() method for an array:

Array.prototype.toString = function() {
  return this.join(' | ');
};

In this example, we define a new function for the Array.prototype.toString() method that joins the elements of the array with a pipe character (|) instead of a comma. The join() method joins the elements of an array into a string with a specified separator. In this case, we use a pipe character as the separator.

Once you have defined the Array.prototype.toString() method, you can call it on an array like you would with the default implementation. For example:

const myArray = [1, 2, 3, 4];
const arrayString = myArray.toString(); // "1 | 2 | 3 | 4"

In this example, we define an array called myArray with four elements. We then call the toString() method on myArray, which returns a string of the array elements separated by pipe characters (|).