JQuery代码无法正常工作

为什么以下代码给出例外？

function SetText(index, text) { try { $('p')[index].innerHTML = text; } catch (ex) { alert(ex); } } $(document).ready(SetText(2, 'Damn')); 

例外是：

 TypeError: $('p')[index] is undefined 

这是我的代码文件：

       ///    function SetText(index, text) { try { $('p')[index].innerHTML = text; } catch (ex) { alert(ex); } } $(document).ready(SetText(2, 'Damn'));    
 
 
This is 1st Paragraph
 
This is 2nd Paragraph
 
This is 3rd Paragraph
 
This is 4th Paragraph
 
This is 5th Paragraph
 
 
   

Answer 1

试试看，告诉我们发生了什么：

 $(document).ready(function() { SetText(2, 'Damn') }); 

我认为在DOM准备好之前调用你的函数。

Answer 2

       
Paragraph 0
 
Paragraph 1
 
Paragraph 2
    

您的代码需要通过检查

 if (typeof $('p')[index] !='indefined')