// locale-sensitive parse import java.lang.Number; //... double doubleResult = 0.; long longResult = 0; Number n = nf.parse ( "-2,123.45" ); if ( n instanceof Long ) { longResult = ( (Long)n ).longValue (); } else if ( n instanceof Double ) { doubleResult = ( (Double)n ).doubleValue (); } // locale sensitive format String display = nf.format( 88899L );