JSFiddle - React, Tailwind, and code Playground

by MD. AL-AMIN

HTML

<body>
<input type="button" value="findIndex(1)" onclick="findIndex(1)">
</body>
</html>

JavaScript

var a = [0,1,2,3,4];
function findIndex(c){
    for(var count = 0; count< a.length; count++){
        if(a[count] == c){
            alert(count);
        }
    }
    alert("No index can be found");
  }