Javascript's associative arrays are nothing but javascript object literals. You can add keys to these objects dynamically if the key is a string using the square brackets notation. For example,
Example
let a = { name: 'Ayush' }; let key = 'age'; // Add the non existing key a[key] = 35; console.log(a)
Output
This will give the output −
{ name: 'Ayush', age: 35 }