用jquery改变h1的文本，

Question

hey guys im trying to change the text of a h1 with jquery. i want to change the text every time enter key is pressed in a text area and the values are numeric values like on first enter the text should be 1 and on other it should be 2 and so on.. This is the code which im using...

Jquery

 <script>
        $('#_co').bind('keypress', function(e) {  //_co is the Id of Text area 
            var code = e.keyCode || e.which;
            var id = 1;
            if(code == 13) {
                var text = $('#_line').text();
                     $('#_line').text(id);
                     id++;
            }

        });
        </script>

Html

<h1 id="_line">0</h4>

Answer 1

Just move your declaration outside of that function,

var id = 1;

$('#_co').bind('keypress', function(e) {  //_co is the Id of Text area 
    var code = e.keyCode || e.which;

     if(code == 13) {
      var text = $('#_line').text();
      $('#_line').text(id);
      id++;
     }

});

And as Rohit said in the comment, You are having an invalid markup, Just close the h1 tag properly,

<h1 id="_line">0</h1>

---

As per your new requirement you can use .append() in your current context.

var id = 1;

$('#_co').bind('keypress', function(e) {  //_co is the Id of Text area 
    var code = e.keyCode || e.which;

     if(code == 13) {
      var text = $('#_line').text();
      $('#_line').append('<br>'  + id);
      id++;
     }

});

DEMO