Question

I have question, how write function to select all chceckbox on form, when all checkbox Id start from some const. string, using pure java script
(without jquery and other frameworks) ? I know how do it using each function from JQuery, but I dont have any idea hwo do it in pure JS.My form ex.

    <form id="myId" name="myForm">
<input type="checkbox"  id="lang_1" value="de"/> DE
<input type="checkbox"  id="lang_2" value="us"/> US
<input type="checkbox"  id="lang_3" value="ru"/> RU
<input type="button" onclick="Select();"  value="Select all"/>
</form>

Answer 1

In your case:

for (i = 1; i<3; i++) {
  document.getElementById('lang_'+i).checked = true;
}