Using ript to operate option select

I. Basic understanding:VaR E = document. getelementbyid ("selectid"); E. options = New Option ("text", "value"); // create an option object, create one or more <option value = "value"> text </option> In the <SELECT> label. Options is an array that contains multiple <option value = "value"> text </option> labels. 1. Properties of the options array:Length ------- Length attribute selectedindex ------ index value of the selected text, which is automatically allocated by the memory (, 2, 3 ....) (The first text value, the second text value, the third text value, and the fourth text value .......) 2. attributes of a single option (obj. Options [obj. selectedindex] is a specified <option> tag ):Text ===== return/specify text value ==== return/specify text, with <option value = "... "> consistent index ====== returns the subscript selected ==== returns/specifies whether the object is selected, if true or false is specified, the selected defaultselected =====returned to check whether the selected object is selected by default. True/false 3. Option Method:Add a <option> label ====== obj. options. add (New ("text", "value") deletes a <option> label ====== obj. options. remove (obj. selectedindex); obtain a <option> label ====== obj. options [obj. selectedindex]. text; modify a <option> label ====== obj. options [obj. selectedindex] = New Option ("new text", "value"); Delete all <option> labels ==== obj. options. length = 0; obtain the value of a <option> tag === obj. options [obj. selectedindex]. value; Note: obj. options in option do not need to be capitalized. Options in new option must be capitalized.

1. Check whether selected
If (objselect. selectedindex>-1 ){
// Indicates the selected
} Else {
// The description is not selected.
}

 

2. dynamically create select

Function createselect (){

VaR myselect = Document. createelement ("select ");
Myselect. ID = "myselect ";
Document. Body. appendchild (myselect );
}

 

3. Add Option

Function addoption (){

// Search for objects by ID,
VaR OBJ = Document. getelementbyid ('myselect ');

// Add an option
OBJ. Add (New Option ("text", "value "));
}

 

4. Delete All option options

Function removeall (){
VaR OBJ = Document. getelementbyid ('myselect ');

OBJ. Options. Length = 0;

}

 

5. delete an option Option

Function removeone (){
VaR OBJ = Document. getelementbyid ('myselect ');

// Index. The sequence number of the option to be deleted. The sequence number of the selected option is used here.

VaR Index = obj. selectedindex;
OBJ. Options. Remove (INDEX );
}

 

6. Obtain the option value.

VaR OBJ = Document. getelementbyid ('myselect ');

VaR Index = obj. selectedindex; // the serial number of the selected option.

Var val = obj. Options [Index]. value;

 

7. Obtain the option text

VaR OBJ = Document. getelementbyid ('myselect ');

VaR Index = obj. selectedindex; // the serial number of the selected option.

Var val = obj. Options [Index]. text;

 

8. Modify Option

VaR OBJ = Document. getelementbyid ('myselect ');

VaR Index = obj. selectedindex; // the serial number of the selected option.

Var val = obj. Options [Index] = New Option ("new text", "New Value ");

 

9. Delete select

Function removeselect (){
VaR myselect = Document. getelementbyid ("myselect ");
Myselect. parentnode. removechild (myselect );
}