将值附加到Javascript中的输入字段

Question

Here i'm trying to append some text to an input field but everytime the old value gets replaced with new value.

HTML

<input type="text" id="taginput" class="input" name="tags">

Javascript

function update(i){
 document.getElementById('taginput').value = i.innerHTML;
  }

no jquery please.

Answer 1

You have to get the old value first, and then add to it

function update(i){
    var elem = document.getElementById('taginput');
    var old  = elem.value;
    elem.value = old + i.innerHTML;
}

or you could add it to with += directly

elem.value += i.innerHTML;

Answer 2

 function update(i){ let elem = document.getElementById('taginput'); elem.value = elem.value + i.innerHtml; // Or elem.value += i.innerHtml; // elem.value = elem.value.concat(i.innerHtml) }