Increment and decrement on the same Div/button in JS-CodePudding

i was wondering how i can increment for example 1 when i click on a button and decrement 1 when i click the second time on this button on the same function.

If someone can explain me ! Thank you

CodePudding user response：

Need some more information. But this seems like an interesting function I just wrote down

function foo() {
  if (foo.value == null) foo.value = 0;
  if (foo.value >= 1) return --foo.value;
  if (foo.value <= 0) return   foo.value;
  return foo.value;
}

CodePudding user response：

quick example (not tested):

<div onclick="clickfunction()">...</div>
<style>
  div[is_selected] { background-color:red; }
</style>
<script>
var counter=0;
function clickfunction(e)
{
  if(counter>=5) return;
  if(e.target.getAttribute('is_selected'))
  {
    counter--;
    e.target.removeAttribute('is_selected');
    return;
  }
  counter  ;
  e.target.setAttribute('is_selected', 1);
}