C ++ sizeof operator
sizeof is a keyword, it is a compile-time operator, used to determine the variable or data type in bytes.
sizeof operator can be used to obtain a class, structure, union, and other user-defined data type size.
Sizeof use the following syntax:
sizeof (data type)
Wherein, data type to calculate the size of data types, including classes, structures, unions, and other user-defined data types.
Try the following examples to understand C ++, sizeof usage. 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 produces the following results, the results will differ according to the use of the machine:
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