Operator precedence and associativity
Level Operators Evaluation Order
1 (high) ( ). [ ] –> :: left-to-right
2 * &! ~ ++ –– + – sizeof new delete right-to-left
3 .* –> * left-to-right
4 * / % left-to-right
5 + – left-to-right
6 << >> left-to-right
7 < <= > >= left-to-right
8 == != left-to-right
9 & left-to-right
10 ^ left-to-right
11 | left-to-right
12 && left-to-right
13 || left-to-right
14 ?: right-to-left
15 = *= /= += –= %= <<= >>= &= ^= |= right-to-left
16 (low) , left-to-rightOperators at the top of the table have higher precedence
than operators below. In expressions beginning with
arguments in the innermost set of parentheses (if any),
programs evaluate operators of higher precedence before
evaluating operators of lower precedence.
Unary plus (+) and unary minus (–) are at level 2, and
have precedence over arithmetic plus and minus at level- The &symbol at level 2 is the address-of operator; the
&symbol at level 9 is the bitwise AND operator. The
symbol at level 2 is the pointer-dereference operator; the
symbol at level 4 is the multiplication operator. In the
absence of clarifying parentheses, operators on the same
level are evaluated according to their left-to-right or
right-to-left evaluation order.
Visual database components
TDBCheckBox A data-aware TCheckBoxcomponent.
TDBComboBox A data-aware TComboBoxcomponent.
TDBEdit A data-aware TEditsingle-line text entry
component.
SSView A data-aware text-only TGridcomponent.
TDBImage A data-aware graphical TImagecomponent.
TDBListBox A data-aware TListBoxcomponent.
TDBLookupComboA data-aware TComboBoxcomponent with the
capability to search a lookup table.
TDBLookupList A data-aware TListBoxcomponent with the
capability to search a lookup table.Operators that may be overloaded
*/ + - % ^ & | ~!,=<>
<= >= ++ –– << >> == != && || *= /= %= ^=
&= |= += -= <<= >>= -> ->* [] () new delete
Operators +, -, *, and &may be overloaded for binary and unary expressions. Operators ., .*, ::, ?:, and sizeofmay not be overloaded.
In addition, =, (), [], and->must be implemented as nonstatic member functions.TDBMemo A data-aware TMemomultiple-line text-entry component.
TDBNavigator A sophisticated database browsing and editing tool.
This component is to database programming what a
remote control is to a video recorder. Users click the
control’s buttons to move through database records,
insert new records, delete records, and perform other
navigational operations.
TDBRadioGroup A data-aware TRadioGroupcomponent.
TDBText A data-aware read-only text component for displaying
database information that you don’t want users to be
able to edit.Nonvisual database components
TBatchMove Performs operations on records and tables, such as updating all records that match a specified argument.
TBlobField A field of indefinite size of a record in a dataset that consists of an arbitrary set of bytes—typically a graphical image
such as a bitmap.
TDatabase Provides additional database services such as server log-ins and local aliases.
TDataSet The immediate ancestor of TDBDataSet.
TDataSource Connects dataset components such as TTableand TQuerywith data-aware components such as TDBEditand TDBMenu.
Every database application needs at least one TDataSourceobject.
TDBDataSet The direct ancestor of TTable, TQuery, and TStoredProc. Most applications use the derived classes TTable, TQuery,
and TStoredProcfor dataset access rather than TDBDataSet. However, functions may pass parameters of this type to
operate on all types of datasets and the results of queries.
TField Provides access to fields in a record.
TFieldDef Defines the structure of physical fields in records. All TFieldobjects do not necessarily have corresponding TFieldDef
objects. For example, calculated TFieldobjects have no physical record fields, and therefore no TFieldDefobjects.
TFieldDefs Holds the TFieldDefobjects that define the physical fields in a data set.
TIndexDef Describes the index of a table.
TIndexDefs Holds the set of all TIndexDefobjects for a table.
TParam Defines parameters for TQueryand TStoredProcobjects.
TParams Holds all parameters for TQueryand TStoredProcobjects.35 0672327112 Last page 11/19/04 12:31 PM Page 912