使用jquery更改输入字段值的问题

Question

HTML

<div id="wrapper">
<p>This is a basic tag input: 
    <input id="tag1" value="alpha,beta,gamma" />
</p>
</div>
<textarea id="tagdetect"></textarea>

script

$("#tagdetect").live("keydown",function(){

    var textTyped=$("#tagdetect").val();
    var text=textTyped.split(" ");
    for(i=0;i<text.length;i++){

        if(text[i]=="sql"||text[i]=="html"||text[i]=="java"){

            $("#tag1").val()=text[i];
        }
    }
});

what i am trying to achieve

I am trying to add tags(ie values) in that input field when certain keywords are detected

Working version

http://jsfiddle.net/7aDak/4839/

Answer 1

You have an error in your jQuery syntax.

Change the following line

$("#tag1").val()=text[i];

To this:

$("#tag1").val(text[i]);

Answer 2

设置您应该使用的值：

 $("#tag1").val(text[i])

Answer 3

Function .val() need to have parameters of what you want to append:

var value = $("#tag1").val();
$("#tag1").val(value + text[i]);

Answer 4

I think this is more elegant apart from fixing your errors - assuming you want all the tags in the field

var types = ["sql","html","java"];

$("#tagdetect").on("keydown",function(){

  var textTyped=$("#tagdetect").val();
  var text=textTyped.split(" ");
  $.each(text,function(_,txt) {
    if ($.inArray(txt,types)!=-1) $("#tag1").append(txt+" ");
  });
});