Name: Macasing, John Rey G.
Block: CHS – 2B
C++ Data Types
In C++, data types are declarations for variables. This determines the type
and size of data associated with variables. For example,
int age = 13;
Here, age is a variable of type int . Meaning, the variable can only store
integers of either 2 or 4 bytes.
C++ Fundamental Data Types
The table below shows the fundamental data types, their meaning, and their
sizes (in bytes):
Data Type Meaning Size ( in Bytes )
int Integer 2 or 4
float Floating-point 4
double Double Floating-point 8
char Character 1
wchar_t Wide Character 2
bool Boolean 1
void Empty 0
1. C++ int.
The int keyword is used to indicate integers.
Its size is usually 4 bytes. Meaning, it can store values from -2147483648 to
2147483647.
For example,
int salary = 85000;
2. C++ float and double
float and double are used to store floating-point numbers (decimals and
exponentials).
The size of float is 4 bytes and the size of double is 8 bytes.
Hence, double has two times the precision of float. To learn more, visit C++
float and double.
For example,
float area = 64.74;
double volume = 134.64534;
As mentioned above, these two data types are also used for exponentials. For
example,
double distance = 45E12 // 45E12 is equal to 45*10^12
3. C++ char
Keyword char is used for characters.
Its size is 1 byte.
Characters in C++ are enclosed inside single quotes ' '.
For example,
char test = 'h';
Note: In C++, an integer value is stored in a char variable rather than the
character itself.
4. C++ wchar_t
Wide character wchar_t is similar to the char data type, except its size is 2
bytes instead of 1.
It is used to represent characters that require more memory to represent them
than a single char .
For example,
wchar_t test = L''ם // storing Hebrew character;
Notice the letter L before the quotation marks.
Note: There are also two other fixed-size character
types char16_t and char32_t introduced in C++11.
5. C++ bool
The bool data type has one of two possible values: true or false .
Booleans are used in conditional statements and loops (which we will learn in
later chapters).
For example,
bool cond = false;
6. C++ void
The void keyword indicates an absence of data. It means "nothing" or "no
value".
We will use void when we learn about functions and pointers.
Note: We cannot declare variables of the void type.
C++ Type Modifiers
We can further modify some of the fundamental data types by using type
modifiers. There are 4 type modifiers in C++. They are:
1. signed
2. unsigned
3. short
4. long
We can modify the following data types with the above modifiers:
int
double
char
C++ Modified Data Types List
Data Type Size (in Bytes) Meaning
signed int 4 used for integers (equivalent to int)
signed int 4 can only store positive integers
short 2 used for small integers (range -32768
to 32767)
unsigned short 2 used for small positive integers (range
0 to 65,535)
long at least 4 used for large integers (equivalent to
long int)
unsigned long 4 used for large positive integers or 0
(equivalent to unsigned long int)
long long 8 used for very large integers
(equivalent to long long int).
unsigned long long 8 used for very large positive integers or
0 (equivalent to unsigned long
long int)
long double 12 used for large floating-point numbers
signed char 1 used for characters (guaranteed
range -127 to 127)
unsigned char 1 used for characters (range 0 to 255)
Let's see a few examples.
long b = 4523232;
long int c = 2345342;
long double d = 233434.56343;
short d = 3434233; // Error! out of range
unsigned int a = -5; // Error! can only store positive
numbers or 0
