string in arrey code example
Example 1: javascript array contains
var colors = ["red", "blue", "green"];
var hasRed = colors.includes("red"); //true
var hasYellow = colors.includes("yellow"); //false
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");
}