如何使用javascript onclick（）获取元素的属性值？

Question

I want to access the id of button , when i write the PHP variable the javascript code create error "Undefined" value.

function update_profile(){ $(function() {
var element = $(this);
var update_id = element.attr("id");
  var infoo = 'updated_id=' + update_id;

    document.getElementsByClassName('test')[0].innerHTML=infoo;


});
}

button code:

<button data-toggle="modal" data-target=".bs-example-modal-lg" onclick="update_profile()"  class="btn-xs btn-warning " id='<?php echo $user_rec[1]; ?>' >Update</button>

Answer 1

You don't need $(function() { }); inside of your function. You have to pass this to your function so it knows which element was clicked.

 function update_profile(element){ var update_id = element.id; var infoo = 'updated_id=' + update_id; document.getElementsByClassName('test')[0].innerHTML = infoo; } 

 <div class="test">test class element</div> <button data-toggle="modal" data-target=".bs-example-modal-lg" onclick="update_profile(this)" class="btn-xs btn-warning " id='idName' >Update</button>