javascript - JQuery check if existing appending element in element if not append to class but not this -

how can prevent reappending element if element in element exists code?

<div class='weekhourvalue' data-nameday='tuesday' data-week='34' data-day='10' data-month='5' data-year='2015'><div class='singleyearevent'></div></div> <div class='weekhourvalue' data-nameday='tuesday' data-week='34' data-day='10' data-month='5' data-year='2016'></div> 

and want somethink this

$(".weekhourvalue[data-month='5'][data-day='10'] {where not exist in element}").append("<div class='singleyearevent'></div>");

is there jquery function this? thank you!

you can try:

$(".weekhourvalue[data-month='5'][data-day='10']").each(function(){     if (!$(this).find(".singleyearevent").length)         $(this).append("<div class='singleyearevent'></div>"); });