JSFiddle - React, Tailwind, and code Playground

HTML

<input></input>
<button>submit</button>


<code></code>

JavaScript

var json = {
    "G1": ["1", "2"],
    "G2": ["3", "4"]
}

$("button").click(function() {

    var input = $("input").val();
    var result = "????";


    for (var key in json) {
        $.each(json[key], function(index, value) {

            if (input == value) {
                $("code").html(key);
                return;
            }
        });
    }

});