javascript - jQuery: Count children of several elements and calculate -

I am creating a website for a restaurant, where they want to make "room" in the menu, the following "5" with.

  Example: Starter 1. 2. Salad 5. 6. 7. 8. 9 10. 11. Pizza 15. 17.  

I have tables Count the numbers within a div, give the tables in this number, then calculate the number of TRS within the tab, add all this together and write it in TD first.

When the second table is added, it will take the last number from the previous table (pre 3) and search the next 5. In this case "5" If the last number was 6, the next table would be 10.

Does this mean?

  
 
 
 The jQuery selector with more than one match will return a jquery object that you can use Are an array In your case, selector  $ ('# menu table')  will give you an array of each table ... Check how you can get TR elements also. 
 
 But I want to propose that with your situation, choosing the right tool can make your life very easy. In this case, have you considered using one instead of table? There are some great features in the ordered lists, such as you can start the numbering form as you like. So there is less mathematics to do this, just select each ordered list, calculate the number of list items, and set SEQNUM to that number. 
 
 So your structure is now: 
 
  & lt; Div id = "menu" & gt; & Lt; Ol & gt; & Lt; Lh & gt; Starter & lt; / Lh & gt; & Lt; Li & gt; Starter items & lt; / Li & gt; & Lt; Li & gt; Starter items & lt; / Li & gt; & Lt; Li & gt; Starter items & lt; / Li & gt; & Lt; / Ol & gt; & Lt; Ol & gt; & Lt; Lh & gt; Salad & lt; / Lh & gt; & Lt; Li & gt; Salad item & lt; / Li & gt; & Lt; Li & gt; Salad item & lt; / Li & gt; & Lt; Li & gt; Salad item & lt; / Li & gt; & Lt; / Ol & gt; & Lt; Ol & gt; & Lt; Lh & gt; Pizza & lt; / Lh & gt; & Lt; Li & gt; Pizza Items & lt; / Li & gt; & Lt; Li & gt; Pizza Items & lt; / Li & gt; & Lt; Li & gt; Pizza Items & lt; / Li & gt; & Lt; / Ol & gt; & Lt; / Div & gt;  
 
 jQuery I will leave in jQuery as a practice ... 
 
 Now if you do not want to write jQuery, just click  & lt < Code> & lt; Ol & gt; Instead of ; AL CONTINUE & gt;  and it does all the numbers for you.