JSFiddle - React, Tailwind, and code Playground

HTML

<a class= "testa" href="" readonly="true">some text</a><br/>
<input type="button" onclick="alerReadonleAttr()" value ="go" />

<script>
    
function alerReadonleAttr(){
    var atr=  $(".testa").attr("readonly");
    var prop=  $(".testa").prop("readonly");
    var getatr=  $(".testa")[0].getAttribute("readonly");
    
    alert("attr: " + atr+"\n prop: "+prop+"\n getAttribute: "+getatr);
}
</script>