217. Explain in detail about various data types in C++.
Answers
Explanation:
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
Now, let us discuss these fundamental data types in more detail.
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. To learn more, visit C++ characters.
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:
signed
unsigned
short
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)
unsigned int 4 can only store positive integers
short 2 used for small integers (range -32768 to 32767)
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 8 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