JSFiddle - React, Tailwind, and code Playground

HTML

<input class="guess" value="" />
<input class="guess" value="" />
<input class="guess" value="" />
<input class="guess" value="" />

JavaScript

$(".guess").bind("blur", function () {
        (findDuplicate(this.value));
    })

    function findDuplicate(value) {
        var result = 0;
        $(".guess").each(function(){
            if (this.value == value) {
                result++;
                  
            }
             alert('duplicate');
        });
     
        
    }