On the option object _javascript skill in the Pull-down menu

1. Create option Object

1.1 var optionEle1 = document.createelement (' option ');

1.2 var optionEle2 = new Option (text, value, defaultselected, selected);

2.options Properties

2.1 Select.options Returns a collection of option objects below the Select label

3. Empty the Pull-down menu

3.1 using for loop deletion, note the dynamic change of array length

3.2 select.options.length = 0;

4. Application

1. Create a Select dynamically

function Createselect () { 
 
    var myselect = document.createelement ("select");  
Myselect.id = "Myselect";  
Document.body.appendChild (Myselect); 
} 

2. Add Options option

function AddOption () { 
 
     //Lookup object based on ID, 
var obj=document.getelementbyid (' Myselect '); 
 
      Add an option 
obj.add (new   option ("Text", "value");  This can only be effective in IE 
obj.options.add (new Option ("text", "value");//This compatible IE and Firefox 
} 

3. Delete all options option

function RemoveAll () { 
var Obj=document.getelementbyid (' Myselect '); 
 
obj.options.length=0; 
 
   } 

4. Delete an option

function Removeone () { 
var Obj=document.getelementbyid (' Myselect '); 
 
      Index, to delete the number of options, here take the current selection of the serial number 
 
    var index=obj.selectedindex; 
Obj.options.remove (index);  
} 

5. Get the value of options option

var Obj=document.getelementbyid (' Myselect '); 
 
var Index=obj.selectedindex; Ordinal number, taking the ordinal number of the currently selected option 
 
var val = obj.options[index].value; 

6. Get Options Option text

var Obj=document.getelementbyid (' Myselect '); 
 
var Index=obj.selectedindex; Ordinal number, taking the ordinal number of the currently selected option 
 
var val = obj.options[index].text; 

7. Modify Options option

var Obj=document.getelementbyid (' Myselect '); 
 
var Index=obj.selectedindex; Ordinal number, taking the ordinal number of the currently selected option 
 
var val = obj.options[index]=new option ("New text", "New value"); 

8. Delete Select

function Removeselect () { 
var myselect = document.getElementById ("Myselect"); 
MySelect.parentNode.removeChild (Myselect); 
} 

<! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01//ZH-CN" "HTTP://WWW.W3.ORG/TR/HTML4/STRICT.DTD" >