Nested foreach loop to linq query

Question

I'm trying to convert the below nested foreach loops to a linq query

foreach (SAP.MOD mod in mods){
    foreach (SAP.RefMod r in refs){
        if (mod.RefModId == r.RefModId){
            modLookup.Add(mod.Modcode, r.ModItem);
            break;
        }
    }
}

Answer 1

Try using join :

var matches = mods.Join(refs,
  m => wo.RefModId,
  r => p.RefModId,
  (mod,ref) => new {mod.RefModId, mod.Modcode, ref.ModItem}
);
matches.All(x => modLookup.Add(x.Modcode, x.ModItem));

Answer 2

var query = from m in mods
            join r in refs on m.RefModIf equals r.RefModId
            select new {
                mod.Modcode,
                r.ModItem,
            };

foreach (var i in query)
    modLookup.Add(i.Modcode, i.ModItem);

... if modLookup is a dictionary you could do this instead of the foreach ...

modLookup = query.ToDictionary(i=>i.Modcode, i=>i.ModItem);