Javascript-寻找替代prependTo的方式，使其不会添加多个项目

Question

I have some code. When it runs correctly, I create a success message and use prependTo in order to display it on the screen. The problem is that when the user does their successful action twice, I end up with two success messages.

Is there a way to overwrite my success message. Here is how I currently handle it in my code:

  $((is_error ? "<p class=' alert alert-error'>"+message+"</p>)" : "<p class=' alert alert-success'>"+message+"</p>")).prependTo("#feedback-container");

Thanks!

Answer 1

可以使用html代替prependTo ，因此您不必先添加而是替换消息容器的内容：

$("#feedback-container").html(is_error ? "<p class=' alert alert-error'>"+message+"</p>" : "<p class=' alert alert-success'>"+message+"</p>");

Answer 2

You can use simply this :

$("#feedback-container").html((is_error ? "<p class=' alert alert-error'>"+message+"</p>)" : "<p class=' alert alert-success'>"+message+"</p>"));

So the entire content of your container is replaced.

Answer 3

$("#feedback-container").children(".alert:first-child").remove().end().prepend( "stuff" );

工作演示http://jsfiddle.net/uVVYN/

Answer 4

By definition prependTo will "inserted at the beginning of the element(s) specified by this parameter." In other words, it will insert but not replace .

What you are looking for is most likely the html method that will set the innerHTML of the matched element with the given content: http://api.jquery.com/html/

The usage of html() is slightly different to prependTo() but conceptually the same:

 $("#feedback-container").html((is_error ? "<p class=' alert alert-error'>"+message+"</p>)" : "<p class=' alert alert-success'>"+message+"</p>"));