What are primitive data types in C++?

What is a variable?

**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.

Primitive data types

The following data types are frequently used in C++: - `int`: This is used to store integer values such as `1`, `-1`, `7`, etc. ```C++ 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";
    
Primitive data types used in C++
Primitive data types used in C++

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.

Example

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;
}

Explanation

- **Line 2:** We'll add `#include ` library for using `string`. - **Line 7:** Initialize an `int` variable `number` and assign a value of `5`. - **Line 8:** Initialize a `float` variable `decimal1` and assign a value of `5.87`. - **Line 9:** Initialize a `double` variable `decimal2` and assign a value of `87.0987`. - **Line 10–11:** Initialize a `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`. - **Line 12:** Initialize a `char` variable `letter` and assign a value `A`. - **Line 13:** Initialize a `string` variable `text` and assign a `Welcome to Educative` value. - **Line 15–20:** Displaying the values of variables by prompting a message.

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