Sign Up ›

Browse by Topic
ShowAll Questionssorted byDate Posted
+ Start a Discussion
sfdc franklinsfdc franklin 

hi how to remove and remove all functionality in list collection .

how to work with , remove and remove all functionality in the salesforce list collection with below code.
  
public class selectoptiontest {

   public set<string>citylist {get;set;}
    public set<selectoption>NotselectedOptions{get;set;}
     public list<string>selectedvallist{get;set;}
  public selectoptiontest(){
        NotselectedOptions= new set<selectoption>();
        selectedvallist= new list<string>();
        citylist= new set<string>();
        citylist.add('mumbai'); 
        citylist.add('maharastra');
        citylist.add('uttarpradesh');
        citylist.add('mumbai'); 
        getdata();
  }
  
  public void getdata(){
    for(string s:citylist){
        NotselectedOptions.add(new SelectOption(s,s));
        }
  }


  public void removeselected(){
        citylist.removeall(selectedvallist);
   }
   
   public void removeall(){
   selectedvallist.clear();
    for(string s:citylist){
    selectedvallist.add(s);
      }
   citylist.removeall(selectedvallist);
    }

 }



v.f page:

  
<apex:page controller="selectoptiontest" >
   <apex:form >
               
                <apex:outputPanel id="t">
              <apex:selectList id="Avilblecities" multiselect="true" tabindex="1"  value="{!selectedvallist}" >  
                     <apex:selectOptions value="{!NotselectedOptions}"/>
                  </apex:selectList>
                  
                  </apex:outputPanel>
                  
                  
                 <apex:commandButton action="{!removeselected}"  rerender="t"   value="removeselected"/>
                  
                   <apex:commandButton action="{!removeall}"  rerender="t"   value="removeAll"/>
                  
   </apex:form>
</apex:page>

can any one help it with it please.

thanks and regards
franklin.
ANUTEJANUTEJ (Salesforce Developers) 
Hi Franklin,

>>  https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_methods_system_list.htm

In the documentation you can use the below functions for your purpose remove to delete a element at a particular index and clear function to remove all the elements in the list.

remove(index)
Removes the list element stored at the specified index, returning the element that was removed.
Signature
public Object remove(Integer index)

Parameters
index
Type: Integer
Return Value
Type: Object

Example 
List<String> colors = new String[3];
colors[0] = 'Red';
colors[1] = 'Blue';
colors[2] = 'Green';
String s1 = colors.remove(2);
system.assertEquals('Green', s1);

clear():
Removes all elements from a list, consequently setting the list's length to zero.

Signature
public Void clear()

Return Value
Type: Void

EDIT: changed the clear description.

Additionally, you can also try checking https://salesforce.stackexchange.com/questions/65670/best-way-to-remove-element-from-list-or-why-they-kept-iterator-without-this-opti

Let me know if it helps you and close your query by marking it as solved so that it can help others in the future.  

Thanks.