Defination: A quantity that cannot change its value during execution of the program is called constant. explanation: constants are the expressions which have fixed value.constants are generally categorized into: Literal,Boolean and symbolic constants.They are used to express particular values within the source code of a program.There are four types of constants in C++.These are: integer constants floating point constants character constants string constants Integer Constants: A numerical value without a decimal part is called integer constants.The plus(+) and minus(-) sings can also be used with an integer constants.Integer constants are used in expressions for calculations.To print an integer constants,it is given in the output statement without quotation marks.For example to print integer constants 220 and 130,the output statements is written as: cout<<220;