In jquery, if the if statement don't return anything, then do nothing

I have a calendar on my web page, and this script will add a class if the day on the task matches the current day. This work if i do have any tasks on that current day. But if i dont, it will give me an error on this current script and all the others script on my web page making the web page useless. So the question is, how to i make jquery just ignore and do nothing if the if statement doesn't return anything?

var d = new Date(2019, 1, 24);
var month = d.getMonth() + 1; //.getMonth() is 0-11
var day = d.getDate();

if (day < 10) {
  day = '0' + dd;
}

if (month < 10) {
  month = '0' + month;
}

 var mydivs = document.getElementsByClassName("mydiv");
 for(var i = 0; i < mydivs.length; i++) {
     if (mydivs[i].children[0].innerHTML == `${day}.${month}`) {
        mydivs[i].className += " today";
     }
 }

.today {
  border: 2px solid red;
  color: red;
}

<div class="mydiv">
    <span class="date-display-single day" property="dc:date" datatype="xsd:dateTime" content="2019-02-24T11:30:00+01:00">24.02</span>
</div>

<div class="mydiv">
    <span class="date-display-single day" property="dc:date" datatype="xsd:dateTime" content="2019-02-25T11:30:00+01:00">25.02</span>
</div>