Programming C# 3.0, 5th Edition

Operators

An operator is a symbol that causes C# to take an action. The C# primitive types (e.g., int) support a number of operators such as assignment, increment, and so forth.

The Assignment Operator (=)

The = symbol causes the operand on the left side of the operator to have its value changed to whatever is on the right side of the operator. Statements that evaluate to a value are called expressions. You may be surprised how many statements do evaluate to a value. For example, an assignment such as:

myVariable = 57;

is an expression; it evaluates to the value assigned, which, in this case, is 57.

Note that the preceding statement assigns the value 57 to the variable myVariable. The assignment operator (=) doesn't test equality; rather, it causes whatever is on the right side (57) to be assigned to whatever is on the left side (myVariable).

Warning

VB programmers take note: C# distinguishes between equality (two equals signs) and assignment (one equals sign).

Because myVariable = 57 (read aloud as "assign the numeric value 57 to the variable whose name is myVariable") is an expression that evaluates to 57, it can be used as part of another assignment operator, such as:

mySecondVariable = myVariable = 57;

In this statement, the literal value 57 is assigned to the variable myVariable. The value of that assignment (57) is then assigned to the second variable, mySecondVariable. Thus, the value 57 is assigned to both variables.

Tip

The value 57 is referred to as a literal value (as opposed to ...