Summary - Data types
- C++ course
- Beginner
- Lesson 18/116
- 5 min
Combine integer, floating-point and string types to write a calculation card.
Summary - Data types
In this section you learned the basic C++ data types:
- int, short, long, long long integer types
- float, double, long double floating-point types
- bool for true/false, char for single characters
- std::string for text
- sizeof to query memory size
Now you will combine these types in two tasks to reinforce what you learned.
Practice Print three types
Add the #include <string> header. Inside main, declare an int (value 42), a double (value 3.14) and a std::string (value "Test"). Print all three in a single std::cout line with spaces (" ") between them and end with std::endl.
Starter code
#include <iostream>
int main() {
// Declare int, double and std::string
// Print all three with std::cout
return 0;
}Sample solution
#include <iostream>
#include <string>
int main() {
// Declare int, double and std::string
int count = 42;
double rate = 3.14;
std::string name = "Test";
// Print all three with std::cout
std::cout << count << " " << rate << " " << name << std::endl;
return 0;
}Expected output
42 3.14 Test
Practice Print a variable's size
Inside main, declare int value = 100;. Use sizeof(value) to print the byte size of value with std::cout using std::endl.
Starter code
#include <iostream>
int main() {
// Declare int value
// Print the size of value with sizeof
return 0;
}Sample solution
#include <iostream>
int main() {
// Declare int value
int value = 100;
// Print the size of value with sizeof
std::cout << sizeof(value) << std::endl;
return 0;
}Expected output
4
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Match types with categories
| Term | Meaning |
|---|---|
int |
Integer |
double |
Floating-point |
char |
Character |
std::string |
Text |
2 Querying size
Question
std::cout << ____(double);
Answer
std::cout << sizeof(double);Explanation: sizeof(double) gives the byte size of double.