Javascript Operations Select Control Daquan (add, modify, delete, select, empty, Judge existence, etc.)

Turn from: http://www.cnblogs.com/zyh-nhy/archive/2007/08/08/847876.html 1 To determine if there is an item value= "Paravalue" in the Select option
2 Add an item to the Select option
3 Remove an item from the Select option
4 Delete selected Items in select
5 Modify the text of value= "Paravalue" in the Select option to "Paratext"
6 Set the first item of text= "Paratext" in Select to be selected
7 Set the item of value= "Paravalue" in Select to be selected
8 Gets the value of the current selected item of select
9 Gets the text of the current selected item of select
10 gets the index of the current selected item of select
11 emptying the Select item

JS Code
1. Determine if the value= "Paravalue" item exists in the SELECT option
function Jsselectisexititem (Objselect, Objitemvalue){
var isexit = false;
for (var i = 0; i < objSelect.options.length; i++){
if (Objselect.options[i].value = = Objitemvalue){
Isexit = true;
Break
}
}
return isexit;
}

2. Add an item to the Select option
function Jsadditemtoselect (Objselect, Objitemtext, Objitemvalue){
Determine if there is
if (Jsselectisexititem (Objselect, Objitemvalue)){
Alert ("The value of the item already exists");
} else{
var varitem = new Option (Objitemtext, Objitemvalue);
ObjSelect.options.add (Varitem);
Alert ("Join successfully");
}
}

3. Remove an item from the Select option
function Jsremoveitemfromselect (Objselect, Objitemvalue){
Determine if there is
if (Jsselectisexititem (Objselect, Objitemvalue)){
for (var i = 0; i < objSelect.options.length; i++){
if (Objselect.options[i].value = = Objitemvalue){
ObjSelect.options.remove (i);
Break
}
}
Alert ("delete successfully");
} else{
Alert ("The item does not exist in this select");
}
}


4. Delete the selected item in select
function Jsremoveselecteditemfromselect (objselect){
var length = objselect.options.length-1;
for (var i = length; I >= 0; i--){
if (objselect[i].selected = = True){
Objselect.options[i] = null;
}
}
}

5. Modify the text of value= "Paravalue" in the Select option to "Paratext"
function Jsupdateitemtoselect (Objselect, Objitemtext, Objitemvalue){
Determine if there is
if (Jsselectisexititem (Objselect, Objitemvalue)){
for (var i = 0; i < objSelect.options.length; i++){
if (Objselect.options[i].value = = Objitemvalue){
Objselect.options[i].text = Objitemtext;
Break
}
}
Alert ("Successful modification");
} else{
Alert ("The item does not exist in this select");
}
}

6. Set the first item of text= "Paratext" in Select to be selected
function Jsselectitembyvalue (Objselect, Objitemtext){
Determine if there is
var isexit = false;
for (var i = 0; i < objSelect.options.length; i++){
if (Objselect.options[i].text = = Objitemtext){
Objselect.options[i].selected = true;
Isexit = true;
Break
}
}
Show out results
if (isexit){
Alert ("Selected successfully");
} else{
Alert ("The item does not exist in this select");
}
}

7. Set the item of value= "Paravalue" in Select to select
Document.all.objSelect.value = Objitemvalue;

8. Gets the value of the current selected item of select
var currselectvalue = Document.all.objSelect.value;

9. Gets the text of the current selected item of select
var currselecttext = Document.all.objselect.options[document.all.objselect.selectedindex].text;

10. Get the index of the current selected item of select
var currselectindex = Document.all.objSelect.selectedIndex;

11. Clear the Select item
document.all.objSelect.options.length = 0;

Javascript Operations Select Control Daquan (add, modify, delete, select, empty, Judge existence, etc.)