javascript - how to simplify this statement using indexOf?

How can I simplfy the following text inside the if statement in Javascript using "indexof"?

if (a === 1 || a === 2 || a === 3) {
  return "correct";
};

I am guessing an array needs to be made for 1,2, and 3, but am unsure of how to us instanceof after that

*edited to say indexOf instead of instanceOf

Answer

The instanceof operator tests whether an object has in its prototype chain the prototype property of a constructor.

In your case, instanceof wont help you. You can use indexOf() with array as follow.

var arr = [1, 2, 3];

// Check if a is present in the arr array
if (arr.indexOf(a) > -1) {
    return "correct";
}