JSFiddle - React, Tailwind, and code Playground

by dife

HTML

<input type="text" id="nome"  required/>
  <input type="submit" id="cadastrar" value="cadastrar" />

CSS

.borda{
  border: 1px solid #f00;
}

JavaScript

$("#cadastrar").on("click", function(){
   
   if( $('#nome').val().length === 0 ) {
         $("#nome").addClass("borda");
    }else{
       alert($("#nome").val());
    }
});