如何避免多次追加

Question

$('.btn-default').click(function()
{
    var foldername = $('#file_title').val();
    $.post ('<?php echo  base_url(); ?>ClientCont/List_Files/inserttitle',{
        file_title:foldername
    },function(data){
        console.log(data);
    if(data['exist']== true ){
        if($('#notifme').length != 0){
            $('#notifme').append("Folder name already exist!");
            $('#notifme').show();
        }
    },'json');
}); 

Just wanted to ask, the code above is used to create a folder if the folder exists, I will notify the user that the folder is already in the database, but if the user click the button multiple times append execute multiple times. Please help how to avoid that #notifme is the name of my id for my alert thanks

Answer 1

您可以使用html（）代替append（）

$('#notifme').html("Folder name already exist!");

Answer 2

The append() method inserts specified content at the end of the selected elements ie It keeps on adding content on each event. html( htmlString ) sets the HTML contents of each element in the set of matched elements ie it will replace the html of selected element with supplied html string. And text( text ) set the content of each element in the set of matched elements to the specified text ie it will replace the content of selected element. So you can use either html( htmlString ) or text( text ) to set the content in element.

 $('button').on('click', function(){ $('#notifme1').text("This is set by text()"); $('#notifme2').html("<b>This is set by html()</b>") }); 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div id="notifme1"> </div> <div id="notifme2"> </div> <button>Click me</button>