how to check a value is in an array js code example

Example 1: get if there is a value in an array node js

myArray = Array(/*element1, element2, etc...*/);

// If the array 'myArray' contains the element 'valueWeSearch'
if(myArray.includes(valueWeSearch))
{
 	// Do something
}

Example 2: javascript check if in array

var extensions = ["image/jpeg","image/png","image/gif"];          
if(extensions.indexOf("myfiletype") === -1){
	alert("Image must be .png, .jpg or .gif");
}