C Assignment Rules Explained

In the C language, the assignment operator (=) is used to assign a value to a variable. The basic rule of assignment is as follows:

1. The value on the right must be a valid expression, which can be a constant, variable, or the return value of a function.
2. The variable on the left must be declared and defined before assignment.
3. The type of the assignment must match the type of the variable, otherwise there will be a type conversion or a compile error.
4. The assignment operation is carried out from right to left, meaning the value on the right will be assigned to the variable on the left.
5. The assignment operation will change the value of the variable on the left side, but it will not change the value of the expression on the right side.
6. The assignment operation can be continuously done, for example a = b = c = 10; the value of c is assigned to b, then the value of b is assigned to a.

In conclusion, the assignment operator is used to assign values to variables, following the rules of type matching and right-to-left evaluation.