Iterate through Map with a List of sObjects

Question

After resolving my issue posted here, I was finally able to get a Map<Id,List<Quote>> variable like I needed, but now I can't seem to iterate through the variable. I have tried things like this:

for(Contact cid : quotes.keyset()){
    System.debug(quotes.get(cid));
}

Results: [ERROR] Incompatible key type SOBJECT:Contact for MAP>

AND

for(List<Quote> q : quotes.values()){
    System.debug(q);
}

Results: System.QueryException: List has more than 1 row for assignment to SObject

Answer 1

Your key in the map is of type Id, so your first for loop should be on Id:

for (Id recordId : quotes.keySet())
{}

Then your value for each of the keys (IDs) is a list of quotes, meaning the second for loop will be on the Quote object:

for (Id recordId : quotes.keySet())
{
    for (Quote quoteRecord : quotes.get(recordId))
    {
        // do something
    }
}

Alternatively if you want to go through all the quotes regardless of the IDs, you can do this:

for (List <Quote> quoteList : quotes.values())
{
    for (Quote quoteRecord : quoteList)
    {
        // do something
    }
}

Answer 2

If you want to iterate over a Map and do some logic for specific keys use this

Map<Integer, String> m= new Map<Integer, String> {1=> 'a', 2=>'b'};

Integer[] n = new Integer[]{};
for (Integer i : m.keySet())
{
    n.add(i);
}
Integer j = 0;
for (String s : m.values())
{        
    if (n[j]== 1) {  // 1 here is value of the key, you can use your value

        //DO something
        system.debug(n[j]+' '+s);    j++;
    }
}