javascript手冊-s1

javascript手冊-s1 相关 the 例子 for the defaultSelected property. 相关form and radio objects selected propertyA Boolean value specifying the current selection state of an option in a select object. 语法selectName.options[index].selected

selectName is either the value of the NAME attribute of a select object or an element in the elements array.

index is an integer representing an option in a select object. Property ofoptions array 描述If an option in a select object is selected, the value of its selected property is true; otherwise, it is false. You can set the selected property at any time. The display of the select object updates immediately when you set the selected property. In general, the selected property is more useful than the selectedIndex property for select objects that are created with the MULTIPLE attribute. With the selected property, you can evaluate every option in the options array to determine multiple selections, and you can select individual options without clearing the selection of other options. 例子See the 例子 for the defaultSelected property. 相关defaultSelected, index, selectedIndex properties selectedIndex propertyAn integer specifying the index of the selected option in a select object. 语法1. selectName.selectedIndex2. selectName.options.selectedIndex

selectName is either the value of the NAME attribute of a select object or an element in the elements array. Property ofselect options array 描述Options in a select object are indexed in the order in which they are defined, starting with an index of 0. You can set the selectedIndex property at any time. The display of the select object updates immediately when you set the selectedIndex property. Both forms of the 语法 specify the same value. In general, the selectedIndex property is more useful for select objects that are created without the MULTIPLE attribute. If you evaluate selectedIndex when multiple options are selected, the selectedIndex property specifies the index of the first option only. Setting selectedIndex clears any other options that are selected in the select object. The selected property of the select object's options array is more useful for select objects that are created with the MULTIPLE attribute. With the selected property, you can evaluate every option in the options array to determine multiple selections, and you can select individual options without clearing the selection of other options. 例子In the following example, the getSelectedIndex() function returns the selected index in the musicType select object: function getSelectedIndex() { return document.musicForm.musicType.selectedIndex}

The previous example assumes that the select object is similar to the following: <SELECT NAME="musicType"> <OPTION SELECTED> R&B <OPTION> Jazz <OPTION> Blues <OPTION> New Age</SELECT>

相关defaultSelected, index, selected properties self propertyThe self property is a synonym for the current window or frame. 语法1. self.propertyName2. self.methodName

propertyName is the defaultStatus, status, length, or name property when self refers to a window object.

propertyName is the length or name property when self refers to a frame object.

methodName is any method associated with the window object. Property offrame, window 描述The self property refers to the current window or frame. Use the self property to disambiguate a window property from a form or form element of the same name. You can also use the self property to make your code more readable. The self property is read-only. The value of the self property is <object nameAttribute>

where nameAttribute is the NAME attribute if self refers to a frame, or an internal reference if self refers to a window. 例子In the following example, self.status is used to set the status property of the current window. This usage disambiguates the status property of the current window from a form or form element called "status" within the current window. Go!相关window property setDate methodSets the day of the month for a specified date. 语法dateObjectName.setDate(dayValue)