Error: Variable does not exist: Commitment__c

Question

I'm trying to uncheck a checkbox on the opportunity object called Commitment

global class UpdateContacts implements Database.Batchable<sObject>
{
   global Database.queryLocator start(Database.BatchableContext BC )
   {
        String str = 'SELECT Id, Commitment__c FROM Opportunity WHERE IsOpen = false';
        return Database.getQueryLocator(str);

   }

    global void execute(Database.BatchableContext BC, List<Opportunity> opportunityToProcess)
     {
     List<Opportunity> opportunityList = new List<Opportunity>();
       for(Opportunity oppObj : opportunityToProcess){
                Commitment__c = true;
            opportunityList.add(oppObj);
          }
        update opportunityList;
        }
   global void finish(Database.BatchableContext BC)
    {
   system.debug('finish');     
    }    
}

Answer 1

Presumably, you're trying to set the Commitment__c field of the opportunity record. You'll want to write it like this:

oppObj.Commitment__c = false;

Where oppOb is the record you're working with, Commitment__c is the field you're working with, and "false" means to uncheck a box (per your original question). If you want to check the box, use "true" instead.

Answer 2

You are just missing the reference of using opportunity instance. Remaining all good.

  global class UpdateContacts implements Database.Batchable<sObject>
  {
  global Database.queryLocator start(Database.BatchableContext BC )
  {
      String str = 'SELECT Id, Commitment__c FROM Opportunity WHERE IsOpen = 
      false';
      return Database.getQueryLocator(str);

   }

global void execute(Database.BatchableContext BC, List<Opportunity> 
 opportunityToProcess)
 {
 List<Opportunity> opportunityList = new List<Opportunity>();
   for(Opportunity oppObj : opportunityToProcess){
            **oppObj.Commitment__c = true**;
        opportunityList.add(oppObj);
      }
    update opportunityList;
    }
  global void finish(Database.BatchableContext BC)
   {
    system.debug('finish');     
   }    
}