javascript - Check for element in array

I'm trying to check if an elements already exists in an array. I know of at least 2 different ways to do so: [1] and [2].

I tested both of them, but get no in both cases:

var myArray = ["Banana", "Orange", "Apple", "Mango"];

if ("Banana" in myArray) {
  console.log("yes")
} else {
  console.log("no") // <--

}

if (typeof myArray["Banana"] === 'undefined') {
  console.log("no") // <--
} else {
  console.log("yes")
}

In both cases I get no. Am I missing something?

Also, which of them is faster?

Here is a fiddle.

Answer

Both of those are doing the almost the same thing: Checking if myArray has a property called "Banana", which it doesn't; it has keys 0,1,2, and 3, and the value at myArray[0] happens to be "Banana".

If you want to check if a string is in an array you can use Array.prototype.indexOf:

if( myArray.indexOf("Banana") >= 0 ) {

  console.log("yes")
} else {
  console.log("no")
}