Check whether the check box is selected

1 <div id="prm_div" style="font-size: 12px;" align="left">2         <form id="cx"  method="post">3             <s:iterator var="item" value="#request.optionPrm" status="status">4                 <span><input class="btn1" type="checkbox" name="checkPrm"  style="margin: 3px 1px 0px 3px;" value="${item.id }" ${item.checked } />${item.text }</span>5             </s:iterator>6         </form>7     </div>

Use jquery to determine whether checked is selected.

1 If ($ (". btn1"). Filter (": checked"). Length = 0) {2 alert ("the metric parameter cannot be blank. Please check it! "); 3}

 

Jquery: checkbox Selector

 

Jquery selector Reference Manual

 

Instance

Hide all <input> elements of type = "checkbox:

$(":checkbox")

 

Definition and usage

: The <input> element of the checkbox selector.

Syntax

$(":checkbox")

 

$ (": Checked") indicates the execution option selected

 

Checkbox application in HTML

Checkbox object

The checkbox object represents a selection box in an HTML form.

In the HTML document, <input type = "checkbox"> every time a checkbox object appears, it is created.

You can access a selection box by traversing the elements [] array of the form, or by using document. getelementbyid ().

Attributes of the checkbox object

Attribute	Description
Accesskey	Set or return the shortcut key for accessing the checkbox.
ALT	Sets or returns the alternative text that does not support checkbox display.
Checked	Sets or returns whether the checkbox should be selected.
Defaultchecked	Return the default value of the checked attribute.
Disabled	Sets or returns whether the checkbox should be disabled.
Form	Returns a reference to a form containing the checkbox.
ID	Sets or returns the checkbox ID.
Name	Set or return the checkbox name.
Tabindex	Sets or returns the checkbox Tab key control order.
Type	Returns the form Element type of the checkbox.
Value	Sets or returns the value of the Value Attribute of the checkbox.

Standard attributes

Attribute	Description
Classname	Sets or returns the class attribute of an element.
Dir	Set or return the direction of the text.
Lang	Set or return the language code of the element.
Title	Sets or returns the title attribute of an element.

Checkbox object Method

Method	Description
Blur ()	Remove the focus from the checkbox.
Click ()	Simulate a mouse click in the checkbox.
Focus ()	Assign focus to the checkbox.