Iterate over map?

Question

How do you iterate over a map?

   //Create State Abbreviation to State Count map
        map <string,decimal>    mapStates   = new map<string,decimal>();

        //Get Employee Counts for each state
        Account accStates = [Select AK__c,AL__c,.....
                             FROM Account WHERE ....];

        //Put those counts into map. 
        mapStates.put('AK', accStates.AK__c);
        //49 other states added to map. 

//Loop through map and save only states that have employees
        for (string key : mapStates.keySet()) {
            if( ?? decimal value is blank ){
                 map.removekey???            
            }
        }

Answer 1

In your pseudocode, you're iterating over the Map's keyset.

To get the corresponding value from the map, you need to call get() just like you normally would.

for(String key :myMap.keySet()){
    Decimal mapValue = myMap.get(key);
}

That said, it seems that you're running into a bit of an X-Y problem here.

Although my solution answers your question as worded, seeing as this is your second question regarding the same general piece of code, your asking this question is a sign that you're trying to solve the underlying problem with an ill-fitting solution.

If you find yourself continuing to struggle with whatever it is you're trying to accomplish in the end, then perhaps it's time to take a step back and re-consider the data model/architecture that you're using.

Having 50 fields to hold counts of employees for each state is a red flag to me. My first instinct would be to create a junction object instead. If you'd like to go further here, you can either ask a new question (with the 'big picture' of what you're trying to accomplish), or I can start up a chat room.

Answer 2

If you like to maintain dynamic behavior, this could be an approach.

1) Create a custom metadata type which will contain Country Initial and Country API Name.

2) Upload all the country initials and API name into that.

3) Now loop through the metadata values and match with the API name from accStates and do your processing logic.

//Create State Abbreviation to State Count map
Map<String, String> countryMapping = Map<String, String>();

//Get Employee Counts for each state
Account accStates = [Select AK__c,AL__c,.....
                     FROM Account WHERE ....];


for(Country_API_Mapping__mdt mdt: [SELECT CountryInitial__c, Country_API__c FROM Country_API_Mapping__mdt])
{
    //49 other states added to map. 
    countryMapping.put(mdt.CountryInitial__c, mdt.Country_API__c);
}

//Loop through map and save only states that have employees
for (String apiName : countryMapping.values()) 
{
    if(accStates.get(apiName) == null)
    {
        //do your processing
    }   
}