The previous article records some CSS-Selector and Custom jQuery-Selector.
Today,let's talk about how to control your wrapped set. $('#someDiv').html('There are '+$('a').size()+' link(s) in the div named someDiv '); function or codedescriptionexamplesize()return the count of elements in the wrapped set$('input').size()hide()make the element(s) unvisible$('#someDiv').hide()get(index)Obtains one or all(if index not be provided) mached in elements in the wrapped set.example1eq() first()Obtains the first element in the wrapped set and return a new wrapped set containing just that element. last() index(element)Finds the passed element in the wrapped set and returns its ordinal index within the set.element can be short by using selector$('img').index($('img#findme')[0]);shorten style:$('img').index('img#findme')add(expression)creates a copy of the wrapped set and adds elements,specified by the expression parameter,to the new set. not(expression) filter(expression)creates a copy of the wrapped set and removes elements from the new set that don't match criteria specified by the value of the expression parameter. has(test) slice(begin,end) $('div').has('img[alt]')map(callback function) each(iterator)Traverses all elements in the matched set,invoking the passed iterator function for each.$('img').each(function(n){ this.alt='this is image['+n+'] with an id of '+this.id;}); example1 Because jQuery allows us to treate the wrapped set as a JavaScript array,we can simple array indexing to obtain any element in the wrapped list by position. for example: To obtain the firsst element in the set of all <img> element with an alt attribution on the page,we can write : var imgElement =$('img[alt]')[0]; equals $('img[alt]').get(0) ok,let's review the previous artical.we can also write: var imgElement =$('img[alt]:first') the difference between them is that the latter one will create a new wrapped set that contains the just element.转载于:https://www.cnblogs.com/Xuhaiyang/archive/2012/07/12/2588393.html
