Question

I m new in jquery and javascript coding and Itries to written a function that.1/63/s an original Value on a textarea if the length of its Value is less than "n" nature. 它没有工作。你们能够解释我如何这样做?

该法典:

$("textarea").focus(function() {
    var text = $(this).val();
    $(this).val(  );
    $(this).blur(function() {
        if($(this).val().lenght<20)
        {
            $(this).val(text);
        }
    });
});

Answer 1

尽管效率不高,但这项工作将:

var text=  ;

$("textarea").focus(function() {
    text = $(this).val();
});

$("textarea").blur(function() {
    if($(this).val().length<20)
    {
        $(this).val(text);
    }
});

Answer 2

页: 1

Once you fix that, you ll find that you re re-attaching the blur event each time but never removing it, meaning you will have tons of listeners attached. Try one or a more generic blur attached only once.

Answer 3

You need to create a closure with a local scope and pass in your variable so that it s local to that scope:

$("textarea").focus(function() {
    var text = $(this).val();
    $(this).val(  );
    (function(initialText) {
        $(this).blur(function() {
            if($(this).val().length < 20)
            {
                $(this).val(initialText);
            }
        });
    })(text);
});

If you don t create such a local scope with a closure, then event handler which you pass to .blur() won t know what text is, since it s not in the scope of this function.

http://jibbering.com/faq/notes/closures/“rel=“nofollow”http://jibbering.com/faq/notes/closures/

Answer 4

您可使用<代码>。见下文。

$("textarea").one( focus , function() {      //will be executed once
    $(this).data( init_val , $(this).val()); //set data with initial value
    $(this).val(  );                         //clear the textarea
}).blur(function() {
    if($(this).val().length<20) {            //Check if entered text val is < 20
       $(this).val($(this).data( init_val ));//If yes, update with initial val
    }
});

友情链接