C # Assignment operators and assignment expressions

Assignment is to assign a new value to a variable. The assignment expressions provided in C # are:

= + = = *=/=%= &=/= ^= <<= >>=

The left operand of an assignment must be an expression of a variable, a property accessor, or an index accessor.

In C #, variables can be assigned sequentially, and the assignment operator is right associated, which means that the right-to-left operators are grouped. For example, an expression like a=b=c is equivalent to A= (b=c).

If the operand types on either side of the assignment operator are inconsistent, type conversion is the first.

7.3.1 Simple Assignment

The "=" operator is called a simple assignment operator. In a simple assignment, the right-hand operand must be an expression of some type, and the type must be implicitly convertible to the left operand type. This operator assigns the value of the right-hand operand to the variable, property, or indexer type as the left operand. The result of a simple assignment expression is the value assigned to the left operand. The result type is the same type as the left operand and is always a value type.

7.3.2 Compound Assignment

Operations such as X-op=y can handle the overloaded method of binary operators that form x op y. Like what:

x+=5; equals x=x+5

x%=3; equals x=x%3

x*=y+1; equals x=x* (y+1)

The steps for compound assignment are as follows:

(1) If the return type of the selected operator can be implicitly converted to the data type of x, perform the operation of x=x op y and, in addition, perform an operation on X only.

(2) Otherwise, the selected operator is a predefined operator, and the return value type of the selected operator can be explicitly converted to the type of X. and y can be implicitly converted to the type of x, then the operation is equivalent to the x= (t) (x op y) operation, where T is the type of x, except that x is executed once.

(3) Otherwise, the compound assignment is invalid and produces a compile-time error.