JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    <textarea pattern="[A-Za-z]{1,100}-[A-Za-z]{1,100}"></textarea>
    <input type="submit" value="Submit"/>
</form>

JavaScript

$(function(){
    $('form').submit(function(e){
        e.preventDefault();
        var valid = $('textarea').val().match(/^[ A-Za-z]{1,}-[ A-Za-z]{1,}((,[ A-Za-z]{1,}-[ A-Za-z]{1,})+)?$/);
        if(valid)
        {
            alert("Valid");
        }
        else 
            alert("Not valid");
    })
})