Adding property to an object conditionally in JavaScript

By using && operator, we can add property to an object conditionally. Say we want to add color property to the following Car object if it is produced after 2000. Doesn’t make much sense but for the sake of the example let’s pretend it does :) Here is how you can accomplish that:

const modelYear = 1996

const Car = {
   brand: 'Toyota',
   ...(modelYear > 2000) && { color: 'red' }
}

The above code snippet will yield the following Car object:

const Car = {
   brand: 'Toyota',
   color: 'red'
}

If you negate the condition, meaning say you have the following:

const modelYear = 2003

const Car = {
   brand: 'Toyota',
   ...(modelYear > 2000) && { color: 'red' }
}

Then the resulting Car object would be:

const Car = {
   brand: 'Toyota'
}

It is that simple. Have fun :)