C++ sizeof operator

C++ Operator

sizeof is a keyword, it is a compile-time operator used to determine the byte size of a variable or data type.

The sizeof operator can be used to get the size of class, structure, union, and other user-defined data types.

The syntax of sizeof is as follows:

sizeof(data type)

In which, data type is the data type to be calculated for size, including class, structure, union, and other user-defined data types.

Try the following example to understand C++ The usage of sizeof in C. Copy and paste the following C++ Program to test.cpp file, compile and run the program.

#include <iostream>
using namespace std;
　
int main()
{
　　　cout << "Size of char: " << sizeof(char) << endl;
　　　cout << "Size of int: " << sizeof(int) << endl;
　　　cout << "Size of short int: " << sizeof(short int) << endl;
　　　cout << "Size of long int: " << sizeof(long int) << endl;
　　　cout << "Size of float: " << sizeof(float) << endl;
　　　cout << "Size of double: " << sizeof(double) << endl;
　　　cout << "Size of wchar_t : " << sizeof(wchar_t) << endl;
　　　return 0;
}

When the above code is compiled and executed, it will produce the following results, which may vary depending on the machine used:

Size of char :　1
Size of int :　4
Size of short int :　2
Size of long int :　4
Size of float :　4
Size of double :　8
Size of wchar_t :　4

C++ Operator