NCERT Computer: Chapter 7 – Introduction to C + + Part 4

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3 Literals

Literals (often referred to as constants) are data items that never change their value during the execution of the program.

The following types of literals are available in C++.

Image of Literals

Image of Literals

Image of Literals

i. Integer constants

Integer constants are whole numbers without any fractional part.

It may contain either + or – sign, but decimal point or commas does not appear in any integer constant.

C++ allows three types of integer constants.

  • Decimal (Base 10)

  • Octal (Base 8)

  • Hexadecimal (Base 16)

Decimal (Base 10)

It consists of sequence of digits and should not begin with 0 (zero). For example 124, - 179, + 108.

Octal integer constants

It consists of sequence of digits starting with 0 (zero). For example, 014, 012.

Hexadecimal integer constant

It consists of sequence of digits preceded by ox or OX. For example OXD, OXC. The suffix l or L and u or U attached to any constant forces it to be represented as a long and unsigned respectively.

ii. Character-constants

A character constant in C++ must contain one or more characters and must be enclosed in single quotation marks.

For example ‘A’, ‘9’, etc. C++ allows nongraphic characters which cannot be typed directly from keyboard, e.g., backspace, tab, carriage return etc.

These characters can be represented by using a escape sequence.

An escape sequence represents a single character

The following table gives a listing of common escape sequences.

Image Character Constants

Image Character Constants

Image Character Constants

iii. Floating constants

They are also called real constants. They are numbers having fractional parts. They may be written in fractional from or exponent form

A real constant in fractional form consists of signed or unsigned digits including a decimal point between digits. For example 3.0, -17.0, -0.627 etc.

(iv) String Literals

A sequence of character enclosed within double quotes is called a string literal.

String literal is by default (automatically) added with a special character ‘\O’ which denotes the end of the string.

Therefore the size of the string is increased by one character. For example “COMPUTER” will be represented as “COMPUTER\O” in the memory and its size is 9 characters.