System.Xml.XmlTextWriter.LookupNamespace C# (CSharp) Method

        int LookupNamespace( string prefix ) {
            if ( useNsHashtable ) {
                int nsIndex;
                if ( nsHashtable.TryGetValue( prefix, out nsIndex ) ) {
                    return nsIndex;
                }
            }
            else {
                for ( int i = nsTop; i >= 0; i-- ) {
                    if ( nsStack[i].prefix == prefix ) {
                        return i;
                    }
                }
            }
            return -1;
        }