Expressions can be used whenever numbers can be used in a resource script file. An expression is a sequence of operators and operands that are evaluated to derive a numeric result. The result of an expression can be used whenever Resource Compiler expects a numeric value. The precedence and associativity of operators will be the same as the standard C programming language. Expressions may be nested within other expressions.
An example of operator precedence is illustrated by the following expression:
3 + 4 * 2
Because the multiplication operator (*) has a higher precedence than the addition operator (+), the computation 4 * 2 will be performed first.
An example of operator associativity is illustrated by the following expression:
8 / 2 * 3
Because both the division (/) and multiplication (*) operators are at the same precedence level, their left-to-right associative property causes the computation 8 / 2 to be performed first.
A Unary Expression consists of one operand and a unary operator.
(-1) is a unary expression.
A Binary Expression contains two operands separated by one operator.
(3 + 4) is a binary arithmetic expression having evaluated value as 7.
(2 < 1) is a binary logical expression having evaluated value as 0 (False).
(1 < 2) is a binary logical expression having evaluated value as 1 (True).
(2 << 1) is a binary left shift expression having evaluated value as 4.
(4 >> 1) is a binary right shift expression having evaluated value as 2.
(15 % 4) is a binary modulus expression having evaluated value as 3 (remainder).
The following example specifies the resource ID as the number 12:
ICON 12 myfile.ico
This same resource ID can also be specified in the form of an expression, as shown here:
#define BASE_ID 10
#define ICON_OFFSET_ID 2
ICON (BASE_ID + ICON_OFFSET_ID) myfile.ico
The constants BASE_ID and ICON_OFFSET_ID will be replaced with their macro values. The result of the evaluated expression (10 + 2) will be 12 which is the same as in the first example. The number 10 and 2 are operands in the expression and the symbol plus (+) is the operator applied on operands 10 and 2.
Although the enclosing parentheses are not required, it is a good practice to enclose the expression in parentheses indicating that the whole expression constitutes a single parameter.
The following table mentions the valid operators that can be used in an expression.
旼컴컴컴컴컴컴컴컴컴컫컴컴컴컴컴컴컴컴컴컴쩡컴컴컴컴컴컴컴컴컴커 쿚perator 쿞ymbol 쿟ype � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿪dd �+ 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿪nd �& 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿪nd if �&& 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿫itwise exclusive or�^ 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿫itwise negation �~ 퀅nary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿫itwise negation 쿙OT 퀅nary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿭ivide �/ 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿮quals �= 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿲reater than �> 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿹eft shift �<< 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿹ess than �< 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿹ess than �< 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿹ogical negation �! 퀅nary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿺inus �- 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿺odulus �% 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿺ultiply �* 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿻ot equal �!= 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿻ot less than �>= 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿻ot greater than �<= 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿽r �| 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 쿽r else �|| 쿫inary � 쳐컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴캑 퀁ight shift �>> 쿫inary � 읕컴컴컴컴컴컴컴컴컴컨컴컴컴컴컴컴컴컴컴컴좔컴컴컴컴컴컴컴컴컴켸
Note: The unary NOT operator is used only in the style field of resource statements. If operator NOT is encountered with the operands in an expression, it will be translated as a ~ character.
Any typecast with an operand will be ignored and a warning message will be generated. For example, the expression ((long)3 + (short)2) has typecast (long) with operand 3 and typecast (short) with operand 2. The typecasts have no effect on expression evaluation.