I want to modify a variable which is inside a function in a class. If I move alert to inside the function block it works. But If it stand outside the {} it doesn´t work.

class test {
    my_test() {
        var var_a = 50;
        var var_b;
        $("input[name='my_input']").click(function() {
            if ($("#radio1").is(":checked")) {
                var_b = 100;
            } else if ($("#radio2").is(":checked")) {
                var_b = 0;
            }
        });
        alert(var_b);
    }
}