jQuery uses the power of CSS selectors. :first-child is an CSS pseudo-class selector and eq() isn't from CSS sintax.
Further reading: http://www.456bereastreet.com/archive/200509/css_21_selectors_part_1/ Maurício -----Mensagem Original----- De: Alex Wibowo Para: jquery-en@googlegroups.com Enviada em: quarta-feira, 25 de fevereiro de 2009 09:43 Assunto: [jQuery] Re: tbody:first-child & thead ahhhhhhhhhhh ok ... now i get it......... sorry for wasting your time, guys... i thought its E F:first-child reads "the first child of E of type F"... i didn't know that it has to explicitly be the first child. I didnt even know that this syntax is CSS thing.... i thought it is jQuery's syntax. Thanks for pointing out to that website! Question.... is :first & :eq(n) also a CSS syntax? Thanks again! On Wed, Feb 25, 2009 at 11:29 PM, Mauricio (Maujor) Samy Silva <css.mau...@gmail.com> wrote: Ops! my faul! sorry. Previous post errata. Read: ...BEFORE the F element ... instead of: ...BEFORE the E element... -----Mensagem Original----- De: Mauricio (Maujor) Samy Silva Para: jquery-en@googlegroups.com Enviada em: quarta-feira, 25 de fevereiro de 2009 09:24 Assunto: Re: [jQuery] Re: tbody:first-child & thead Hi Alex, 1-) Doesn't work because * E F:first-child * pseudo-class selector matches the F element that is the first child of the E element ONLY if there isn't another element BEFORE the E element within the parent E. See specs at: http://www.w3.org/TR/CSS2/selector.html#first-child 2-) If you have a thead or/and a tbody in your markup, to select the first thead use the pseudo-class :eq instead. $("#myTable tbody:eq(0) tr").length ) Maurício -----Mensagem Original----- De: Alex Wibowo Para: jquery-en@googlegroups.com Enviada em: quarta-feira, 25 de fevereiro de 2009 08:33 Assunto: [jQuery] Re: tbody:first-child & thead Hi Karl.. thanks for the reply... what i actually wanted is.... to select the first tbody.... thats why i specified tbody:first-child there.... since a table can have multiple tbody... i want to select the first tbody. What I didnt understand is.... about the thead.. the following works.... <table id="myTable"> <tbody> <tr> .... </tr> </tbody> </table> $("#myTable tbody:first-child tr").length; but this doesnt work: <table id="myTable"> <thead> <tr> ... </tr> </thead> <tbody> <tr> .... </tr> </tbody> </table> $("#myTable tbody:first-child tr").length; I dont know how thead causes the second code above not to work... On Wed, Feb 25, 2009 at 8:11 PM, Karl Rudd <karl.r...@gmail.com> wrote: tbody:first-child doesn't select the "first child of the tbody" it says "select the tbody that is the 'first-child' of it's parent". So what you are actually wanting to say is: $("#myTable tbody tr:first-child") Which is "select the tr that is the first child of tbody" http://docs.jquery.com/Selectors/firstChild Karl Rudd On Wed, Feb 25, 2009 at 8:08 PM, Alex Wibowo <alexwib...@gmail.com> wrote: > sorry.... i should say.... > "how does that explain the behaviour when there's no thead" (because it > works when thead doesnt exist) > > On Wed, Feb 25, 2009 at 8:06 PM, Alex Wibowo <alexwib...@gmail.com> wrote: >> >> how does that explain the behaviour when there's thead then?? >> >> >> On Wed, Feb 25, 2009 at 7:47 PM, David Muir <davidkm...@gmail.com> wrote: >>> >>> It's because tbody:first-child is already selecting the tr, so you're >>> effectively doing: >>> tbody tr tr (where the first tr is the first child of tbody) >>> >>> Cheers, >>> David >>> >>> >>> Alex Wibowo wrote: >>>> >>>> Hi all, >>>> >>>> I have a code that counts the number of rows in a table... >>>> >>>> the table looks like: >>>> >>>> <table id="myTable"> >>>> <thead> >>>> ... >>>> </thead> >>>> >>>> <tbody> >>>> <tr> >>>> .... >>>> </tr> >>>> </tbody> >>>> </table> >>>> >>>> >>>> and my jquery looks like: >>>> >>>> $("#myTable tbody:first-child tr").length; >>>> >>>> strange enough.... that always returns 0. >>>> but if i remove the thead from the table... then it will return the >>>> correct number of rows.. >>>> >>>> or alternatively, i can keep the thead, but use the following instead: >>>> >>>> $("#myTable tbody tr").length; >>>> >>>> i.e. without specifying first-child. >>>> >>>> Can anyone explain this behaviour? >>>> >>>> >>>> >>>> THanks a lot! >>>> >>>> >>>> >>>> -- >>>> Best regards, >>>> >>>> >>>> WiB >>>> >>> >> >> >> >> -- >> Best regards, >> >> >> WiB >> > > > > -- > Best regards, > > > WiB > > -- Best regards, WiB -- Best regards, WiB
