Dynamically find field value from Map

Question

Currently I'm looping through values, based on the loop # I want to be able to get different field values.

Example:

Integer years = 1;
for(Integer i = 1; i <= formYears; i++){
String fieldName = 'year_'+i+'__c';
Decimal increase = map.get(key).fieldName;//Here is the issue, can't use String! years = years + 1;
}

Is this possible? Any suggestions?

Answer 1

If the item you are accessing from your map is an sObject, you can get the value of a field thusly:

// Create something we can then query
Account acc = new Account(Name='Test Account');
// Access the Name field 
System.debug(acc.get('Name'));

I believe this will work with Custom Objects, and Custom Fields, but not with inner classes. However, if you are using an inner class then you have control of the code so could do things differently :)

So for your specific case you'd do something like

Integer years = 1;
for(Integer i = 1; i <= formYears; i++){
    String fieldName = 'year_'+i+'__c';
    Decimal increase = map.get(key).get(fieldName); 
    years = years + 1;
}