javascript custom function for changing dates

Question

I have a trouble with a custom function that I've done.

In fact it does not work and I really do not know why.

Here is the function:

<script type="text/javascript">
function lz(x){
    return x.toString().replace(/^(\d)$/,'0$1')
}
function dayplus(){
  var items = document.getElementsByClassName("datepicker hasDatepicker");
  for (var i = 0; i < items.length; i++){
    if (items[i].getAttribute('required')){
      var itemDtParts = items[i].value.split("-");
      var itemDt  = new Date(parseInt(itemDtParts[2],10), parseInt(itemDtParts[1],10)-1, parseInt(itemDtParts[0],10)+ +nb);
      items[i].value = lz(itemDt.getDate())+"-"+lz(itemDt.getMonth()+1)+"-"+itemDt.getFullYear();
    }
  }
}
​</script>

It says to me:

Uncaught SyntaxError: Unexpected token ILLEGAL addday.html:20

Moreover it says to me that the function is undefined or it is not the case.

Here below is the form I use with the function:

<input type="text" class="datepicker hasDatepicker" required value="26-10-2012">

<input type="button" value="( - )" width="22" height="22" onClick="subday()" />
                  <input name="jours" type="text" value="" size="5" id="nb" />
                  <input type="button" value="( + )" width="22" height="22" onClick="dayplus()"  />​​​​​

Answer 1

I made a fiddle here

The first thing I noticed, is that your markup looks strange. Shouldn't it be

<input type="text" class="datepicker hasDatepicker" required="true" value="26-10-2012">

instead of

<input type="text" class="datepicker hasDatepicker" required value="26-10-2012">

The second thing is the invalid syntax, as pointed out by enhzflep and Kimo_do, nb is not defined and + + nb . I replaced it by 1 in the fiddle.

Answer 2

,10)+ +nb); should be ,10)+ nb); perhaps? or ,10)+ (+nb) ); if nb may be negative. That is to say - it looks like an added +. On closer looking, I'm also wondering if you actually mean nb.value or it's longhand: document.getElementById('nb').value?

Or in code:

var itemDt  = new Date(parseInt(itemDtParts[2],10), parseInt(itemDtParts[1],10)-1, parseInt(itemDtParts[0],10) + document.getElementById('nb').value) );

Answer 3

Modified code: jsfiddle . changes: nb was missing, you were using + + to add nb

<input type="text" class="datepicker hasDatepicker" required=true value="26-10-2012">

<input type="button" value="( - )" width="22" height="22" onClick="subday()" />
                  <input name="jours" type="text" value="" size="5" id="nb" />
<input type="button" value="( + )" width="22" height="22" onClick="dayplus()"  />


<script type="text/javascript">
function lz(x){
     return x.toString().replace(/^(\d)$/,'0$1');
}
function dayplus(){
  var items = document.getElementsByClassName("datepicker hasDatepicker");
     nb = 1;
  for (var i = 0; i < items.length; i++){
    if (items[i].getAttribute('required')){
      var itemDtParts = items[i].value.split("-");

      var itemDt  = new Date(itemDtParts[2], parseInt(itemDtParts[1] ,10)-1, parseInt(itemDtParts[0],10) +nb);

      items[i].value = lz(itemDt.getDate())+"-"+lz(itemDt.getMonth()+1)+"-"+itemDt.getFullYear();

    }
  }
}
</script>