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megsumamegsuma 

Looping over Nested Maps

Man, once you start programming for Salesforce you really realize what a pain it can be moving from a weak-typed language (cough PHP) to a strongly typed language like Apex. Trying to replicate the familiar behavior of nested arrays in Apex has proven to be quite difficult.

 

So, I have a nested map defined:

 

 

Map<String, Map<String, List<Decimal>>> return_data = new Map<String, Map<String, List<Decimal>>>();
 
 Further down in my code, I'm attempting to loop this map with a for loop:
 
for(Map<String, Map<String, List<Decimal>>> c_data : return_data)
{
...
}
 
However, the server complains: 
 
 
Save error: Loop must iterate over a collection type: MAP:String,MAP:String,LIST:Decimal 
 
What am I missing here? 
 


ColinKenworthy2ColinKenworthy2
Lets simplify it by replacing the nested map by an object
 
Map<String, OBJ__c> myMap = new ....
so to iterate through this you can either
 
for (String myStr : myMap.keySet()) { OBJ__c myObj = myMap.get(myStr); ... }

or

for (OBJ__c myObj : myMap.values()) { ... }
 
now imagine your nested map in place of the object
 
for (String myStr : myMap.keySet()) { Map<String,List<Decimal>> myNestedMap = myMap.get(myStr); ... }
 
or
 
for (Map<String,List<Decimal>> myNestedMap : myMap.values()) { ... }
 
 
 
You can then nest some for loops so you can iterate over the nested maps as well.