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");
   }
}

Answer 2

Fixed case sensitivity issue using toLowerCase(). It turns all the string to lower case while comparing.

var product=productList.filter((x) => x.Name.toLowerCase().includes(("Active").toLowerCase()))

Answer 3

ES6 array method filter() can simply the solution in single line, use includes() method to determines whether an array includes a certain value among its entries.

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

// convert each string from filterstrings and passedinstring to lowercase
// to avoid case sensitive issue.
filteredStrings = filterstrings.filter((str) => str.toLowerCase().includes(passedinstring.totoLowerCase())

Answer 4

You can simply convert the passedinstring to lowercase.

var passedinstring = localStorage.getItem("passedinstring").toLowerCase();

Answer 5

You can create a RegExp from filterstrings first

var filterstrings = ['firststring','secondstring','thridstring'];
var regex = new RegExp( filterstrings.join( "|" ), "i");

then test if the passedinstring is there

var isAvailable = regex.test( passedinstring ); 

Answer 6

My option is comparing UPPER with UPPER or lower with lower transforming both sides (i did it often in SQL):

    var filterstrings = ['firststring','secondstring','thirDstrIng'];
    var passedinstring =  'ThIrDsTrInG3';
    
    //used for of just to make it more readable
    for (filterstring of filterstrings) {
        if (passedinstring.toUpperCase().includes(filterstring.toUpperCase())) {
            alert("string detected");
        }
    
    }

Prompts string detected