判断对象是否为空 js与Jquery区别

in cn •  6 years ago 
  1. js
    if(document.getElementById('id')==null)

2 Jqurey

     if($('#id').length==0)

     注意：不可用$('#id')==null判断，因为$('#id')总是返回JQuery对象
cn js jquery
6 years ago by

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      ·  6 years ago 

    受教

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