Assignment Operator

Last Updated: April 30, 2012

Definition - What does Assignment Operator mean?

An assignment operator is the operator used to assign a new value to a variable, property, event or indexer element in C# programming language. Assignment operators can also be used for logical operations such as bitwise logical operations or operations on integral operands and Boolean operands.

Unlike in C++, assignment operators in C# cannot be overloaded directly, but the user-defined types can overload the operators like +, -, /, etc. This allows the assignment operator to be used with those types.

Techopedia explains Assignment Operator

The following are the characteristics of assignment operators:

When using the "=" operator for an assignment with the left operand as the property or indexer access, the property or indexer must have a set accessor.
Overloading a binary operator implicitly overloads its corresponding assignment operator (if any).
The different assignment operators are based on the type of operation performed between two operands such as addition (+=), subtraction, (-=), etc. The meaning of the operator symbol used depends on the type of the operands.
Assignment operators are right-associative, which means they are grouped from right to left.
Although assignment using assignment operator (a += b) achieves the same result as that without ( =a +b), the difference between the two ways is that unlike in the latter example, "a" is evaluated only once.
The assignment operator usually returns a reference to the object so as to be used in multiple assignments made in a single statement such as "a=b=c", where a, b and c are operands.
The assignment operator expects the type of both the left- and right-hand side to be the same for successful assignment.

In C#, an expression using an assignment operator might be "x op y", where x and y are operands and "op" represents the operator. The simple assignment operator "=" is used to store the value of its right-hand operand into the memory location denoted by the left-hand operand. The result is its return value. The other assignment operators that perform indicated operation on the two operands and assign a resulting value to the left operand are called compound assignment operators. These include: