Variables & Data Types
Learn C++ data types: int, float, double, char, bool, string. Declare variables and output them with cout.
25 min•By Priygop Team•Last updated: Feb 2026
Variables in C++
C++ is statically typed — you must declare the type of every variable. C++ adds the bool type (true/false) and the string class (from <string>) compared to C. Variables must be declared before use. Use descriptive names and camelCase or snake_case style.
C++ Data Types
- int — Whole numbers: int age = 25;
- float — Decimal (less precise): float price = 9.99f;
- double — Decimal (more precise): double pi = 3.14159;
- char — Single character: char grade = 'A';
- bool — True or false: bool isStudent = true;
- string — Text (from <string>): string name = "Alice";
- auto — Let compiler deduce type: auto x = 42;
Variables Example
Example
#include <iostream>
#include <string>
using namespace std;
int main() {
// Declaring variables
string name = "Alice";
int age = 25;
double height = 5.6;
bool isStudent = true;
char grade = 'A';
// Output with cout
cout << "Name: " << name << endl;
cout << "Age: " << age << endl;
cout << "Height: " << height << " feet" << endl;
cout << "Student: " << isStudent << endl;
cout << "Grade: " << grade << endl;
// auto keyword
auto score = 95; // compiler deduces int
cout << "Score: " << score << endl;
return 0;
}Try It Yourself: Variables
Try It Yourself: VariablesC++
C++ Editor
✓ ValidTab = 2 spaces
C++|24 lines|594 chars|✓ Valid syntax
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