jQuery实时计算输入框字数代码

js代码

<script src=\"js/jquery-1.8.3.min.js\"></script>
<script>
	$(document).ready(function(){

		var lenInput = $(\'.textarea-item\').val().length;

		$(\".textarea-item\").keyup(function(){
			lenInput = $(this).val().length;
			if(lenInput>0 && lenInput<=300){
				$(\'.textareaInput\').html(lenInput);
				$(\'.textarea-btn\').attr(\'disabled\',false);
			}else{
				$(\'.textarea-btn\').attr(\'disabled\',true);
			}
		});
	});
</script>