What is the error in "while (y * z > 0) & (y % 10 == z % 10)"?

Question

It keep saying "lvalue required as unary '&' operand".

Answer 1

Conditions are concatenated by the AND operator &&, the single ampersand & is a different operator. Also, the entire condition should be enclosed in parentheses, not only the left and right side of &&, if that is what you are going for.