How to generate array key using array index – JavaScript associative array?

For this, use forEach() along with [] to an associative array.

Example

Following is the code −

var result = {};
var names = ['John', 'David', 'Mike', 'Sam', 'Bob', 'Adam'];
names.forEach((nameObject, counter) => {
   var generatedValues = { [nameObject]: counter };
   Object.assign(result, generatedValues)
})
console.log(result);

To run the above program, you need to use the following command −

node fileName.js.

Here, my file name is demo290.js.

Output

This will produce the following output on console −

PS C:\Users\Amit\javascript-code> node demo290.js
{ John: 0, David: 1, Mike: 2, Sam: 3, Bob: 4, Adam: 5 }