c# - Do Enumerable.FirstOrDefault() stop when it finds item? -

i tried searching on msdn, , on web not find answer.

say have collection in firstordefault(). let finds item. stop , returns item or continue searching , hampers performance?

if still vague on this, source code in .net framework implemented here:

public static tsource firstordefault<tsource>(this ienumerable<tsource> source) {     if (source == null) throw error.argumentnull("source");     ilist<tsource> list = source ilist<tsource>;     if (list != null) {         if (list.count > 0) return list[0];     }     else {         using (ienumerator<tsource> e = source.getenumerator()) {             if (e.movenext()) return e.current;         }     }     return default(tsource); }  public static tsource firstordefault<tsource>(this ienumerable<tsource>source, func<tsource, bool> predicate) {     if (source == null) throw error.argumentnull("source");     if (predicate == null) throw error.argumentnull("predicate");     foreach (tsource element in source) {         if (predicate(element)) return element;     }     return default(tsource); } 

apparently, stop if founded