JSFiddle - React, Tailwind, and code Playground

by Michael Darmanin

HTML

<div id="choice"></div>

<div id="hidden">

</div>

CSS

#hidden {display:none}

JavaScript

function searchNames(logins){
 var str = "_";
 for (var i = 0; i != logins.length; i++) {
     var substring = logins[i];
     if (str.indexOf(substring) != - 1) {
         return substring;
        }
    }
        return null; 
}

document.getElementById('choice').innerHTML = searchNames([ [ "marco", "[email protected]" ], [ "john", "[email protected]" ] ]);

//should output [ [ "bar_", "[email protected]" ] ]