Assignment operator in C++ is used to assign a value to another variable.
a = 5;
This line of code assigns the integer value 5 to variable a.
The part at the left of the =operator is known as an lvalue (left value) and the right as rvalue (right value). Lvalue must always be a variable whereas the right side can be a constant, a variable, the result of an operation or any combination of them.
The assignment operation always takes place from the right to left and never at the inverse.
One property which C++ has over the other programming languages is that the assignment operator can be used as the rvalue (or part of an rvalue) for another assignment.
Example:
a = 2 + (b = 5);
is equivalent to:
b = 5;
a = 2 + b;
Which means, first assign 5 to variable b and then assign to a, the value 2 plus the result of the previous expression of b(that is 5), leaves a with a final value of 7.
Thus, the following expression is also valid in C++:
a = b = c = 5;
assign 5 to variables a, b and c.
