JavaScript: Simple way to check if variable is equal to one of two or more values?

Question

Is there an easier way to determine if a variable is equal to a range of values, such as:

if x === 5 || 6 

rather than something obtuse like:

if x === 5 || x === 6

?

Answer 1

You can stash your values inside an array and check whether the variable exists in the array by using [].indexOf:

if([5, 6].indexOf(x) > -1) {
  // ...
}

If -1 is returned then the variable doesn't exist in the array.