We do this using an Array of Arrays containing two elements that are each key/value pairs, which looks like this: Using the following syntax, we can recreate the same Map: Note: This example uses trailing commas, also referred to as dangling commas. So we should use map methods: set, get and so on. As the map is an object in JavaScript, it is defined by using new keyword. As an example, initialize an object with a numerical key and compare the value for a numerical 1 key and a stringified "1" key: This is why if you attempt to use an Object as a key, it will print out the string object Object instead.