An assignment operation assigns the value of the right-hand operand to the storage location named by the left-hand operand. Therefore, the left-hand operand of an assignment operation must be a modifiable l-value. After the assignment, an assignment expression has the value of the left operand but is not an l-value.
Syntax
assignment-expression :
conditional-expression
unary-expression assignment-operator assignment-expression
assignment-operator : one of
= *= /= %= += –= <<= >>= &= ^= |=
The assignment operators in C can both transform and assign values in a single operation. C provides the following assignment operators:
| Operator | Operation Performed |
| = | Simple assignment |
| *= | Multiplication assignment |
| /= | Division assignment |
| %= | Remainder assignment |
| += | Addition assignment |
| –= | Subtraction assignment |
| <<= | Left-shift assignment |
| >>= | Right-shift assignment |
| &= | Bitwise-AND assignment |
| ^= | Bitwise-exclusive-OR assignment |
| |= | Bitwise-inclusive-OR assignment |
In assignment, the type of the right-hand value is converted to the type of the left-hand value, and the value is stored in the left operand after the assignment has taken place. The left operand must not be an array, a function, or a constant. The specific conversion path, which depends on the two types, is outlined in detail in Type Conversions.