You may see the javascript drop-down menu when you browse the Web page. This article introduces the use of javascript to implement cascading drop-down list instances. For more information, see, to help you, Html dom refers to some dom operations supported by various browsers before the w3c standard emerged.
1. Select object.
Attribute
A, selectedIndex: subscript of the selected option. The subscript starts from 0.
B, length: Get or set the number of options
C, options: returns an array. The array element is an Option object.
2. Options object
Attribute:
A, text: Option text content
B, value: Optional values
C, selected: If this option is selected, the value is true; otherwise, the value is false.
TIPS: Create an Option object
The Code is as follows:
Var op = new Option (text, value );
A cascade drop-down list I wrote:
The Code is as follows:
The Code is as follows:
