Hello,

I have a list of custom objects. 

I want to update an element of this list so I remove it and then add it (it's the only thing I've found). 

I refered to the list methods and the example here : http://www.salesforce.com/us/developer/docs/apexcode/Content/apex_methods_system_list.htm

But when I refresh the page, there is an error saying the elemnt is duplicate. I checked the log with some system.debug and it is indeed not removed from the list. Can someone explain why ? 

I tried both : 

myList.remove(2)       and 

whateverObject__c removedObj = myList.remove(2) 

Here is the code of the controller : 

public List<Production__c> production { get; set; }
  
    
    public List<Production__c> getName() {
        if(production== null) 
            production= [SELECT ID_Prod__c, name, Tech_name__c, S1__c
                         FROM Production__c 
                         WHERE ID_Prod__c = 1 OR ID_Prod__c = 2 OR ID_Prod__c = 3
                         ORDER BY ID_Prod__c ];
      
        
       Production__c prodAvai = new Production__c(Name='Available', 
                                                   Tech_name__c='AVASTO0', 
                                                   S1__c= 44,
                                                 ID_Prod__c=3);
       
        
      
        production.remove(2);  
        /* or as the doc says : 
        Production__c prodRemoved = production.remove(2);
        */

        Integer nb = production.size();
        System.debug('nb element after rm ' + nb);
        production.add(prodAvai);    // won't work because production[2] is still here 
      
       
        // loop to check the list
        for(Integer i = 0; i < production.size(); i++)
            System.debug('élément ' + i + ' = ' + production[i]);
         

        return production;
    }