Assigning a contact Email address to String

Question

I have the following error for this code "Illegal assignment from Contact to String "

system.debug gives me email address, but its giving me error when I want to insert that value into that custom field inside the opportunity

List<Contact> allContacts = [Select Email From Contact where AccountId=: account.id Limit 1];
      for (Contact currentContact : allContacts) {
        System.debug('Current Contact Email' +  currentContact);
        Opportunity.Email_1__c = currentContact.toString();
                      }

      System.debug('contat' + allContacts);

Answer 1

You need to assign the Email field of Contact that you queried:

Opportunity.Email_1__c = currentContact.Email;

You can see a string version of an SObject such as Contact but that shows the names and values of all the populated fields rather than the single field value you require.

PS

To find out what is going on for your "empty field problem":

System.debug('contact Email ' + currentContact.Email);
Opportunity.Email_1__c = currentContact.Email;
System.debug('opp Email ' + Opportunity.Email_1__c);