37.What is a string literal? What are the rules to be followed to form a string literal? 38.What is a variable? Explain the differences between variables and constants. 39.What are the rules to be...

37.What is a string literal? What are the rules to be followed to form a string literal?

38.What is a variable? Explain the differences between variables and constants.

39.What are the rules to be followed to define and use a variable in C++?

40.Explain the following with suitable examples:

(b) integer variable (b) real variable

(c) character variable (d) bool variable