javascript includes() case insensitive

Question

lets say I have an array of filter strings that I need to loop and check against with other passed in string.

var filterstrings = [\'firststring\',\'secondst         


        

Answer 1

convert filterstring and passedinstring to lowercase and compare

var filterstrings = ['firststring','secondstring','thridstring'];
var passedinstring = 
localStorage.getItem("passedinstring").toLowerCase();

for (i = 0; i < filterstrings.lines.length; i++) {
   if (passedinstring.includes(filterstrings[i].toLowerCase())) {
       alert("string detected");
   }
}