User manual

244
mikoC PRO for PIC32
MikroElektronika
Assignment Operators
Unlike many other programming languages, C treats value assignment as operation (represented by an operator)
rather than instruction.
Simple Assignment Operator
For a common value assignment, a simple assignment operator (=) is used:
expression1 = expression2
The expression1 is an object (memory location) to which the value of expression2 is assigned. Operand expression1
has to be lvalue and expression2 can be any expression. The assignment expression itself is not lvalue.
If expression1 and expression2 are of different types, the result of the expression2 will be converted to the type
of expression1, if necessary. Refer to Type Conversions for more information.
Compound Assignment Operators
C allows more comlex assignments by means of compound assignment operators. The syntax of compound assignment
operators is:
expression1 op= expression2
where op can be one of binary operators +, -, *, /, %, &, |, ^, <<, or >>.
Thus, we have 10 different compound assignment operators: +=, -=, *=, /=, %=, &=, |=, ^=, <<= and >>=. All
of them associate from right to left. Spaces separating compound operators (e.g. + =) will generate error.
Compound assignment has the same effect as
expression1 = expression1 op expression2
except the lvalue expression1 is evaluated only once. For example, expression1 += expression2 is the same
as expression1 = expression1 + expression2.
Assignment Rules
For both simple and compound assignment, the operands expression1 and expression2 must obey one of the
following rules:
1. expression1 is of qualied or unqualied arithmetic type and expression2 is of arithmetic type.
2. expression1 has a qualied or unqualied version of structure or union type compatible with the type of
expression2.
3. expression1 and expression2 are pointers to qualied or unqualied versions of compatible types
and the type pointed to by left has all qualiers of the type pointed to by right.