Variables are a fundamental part of programming. In C++, a data type is used to declare or define each variable. For instance, if a variable can hold integers or if it can also store other symbols.
The following data types are frequently used in C++:
int
: This is used to store integer values such as 1
, -1
, 7
, etc.
int i = 5;
float
and double
: Both these data types store floating point values such as 1.56
, 2.87
, -4.7
, etc. The difference between these two data types is the size. We can store up to 8 bytes in a double
variable while only 4 in a float
variable.
float f = 5.65;
double d = 7.8987;
bool
: This is used to store two states: true
/1
or false
/0
. If we want to store a number with a more significant value, our choice would be double
.
bool b = true;
// or we can also declare bool as this
bool b = 0;
char
: This is used to store a single character value such as a
, A
, #
, etc.
char c = 'A';
string
: This is used to store text such as Welcome to Educative
, @Answers
, etc.
string s = "This is a string";
Except for the last data type, “string,” which is only accessible in the string
library, all the data types mentioned above are available in the iostream
library. String usage requires adding #include <string>
at the beginning of the code.
The following code demonstrates the usage of the data types mentioned above.
#include <iostream>#include <string>using namespace std;int main(){int number = 5;float decimal1 = 5.87;double decimal2 = 87.0987;bool state1 = true;bool state2 = 0;char letter = 'A';string text = "Welcome to Educative";cout << "The integer value is: " << number << endl;cout << "The float value is: " << decimal1 << endl;cout << "The double value is: " << decimal2 << endl;cout << "We can write boolean value in two forms as: " << state1 << " and " << state2 << endl;cout << "The character value is: " << letter << endl;cout << "The string value is: " << text << endl;return 0;}
#include <string>
library for using string
.int
variable number
and assign a value of 5
.float
variable decimal1
and assign a value of 5.87
.double
variable decimal2
and assign a value of 87.0987
.bool
variable state1
and state2
and assign a value true
and 0
, respectively. Another way to assign value to a bool is to assign 0
/1
to the variable. But when we print the value of state1
it prints 1
, not true
.char
variable letter
and assign a value A
.string
variable text
and assign a Welcome to Educative
value.