c++之关于如何确定系统各个整形变量的能表示的最大值和所占内存

// limits.cpp -- some integer limits
#include 
#include               // use limits.h for older systems
int main()
{
    using namespace std;
    int n_int = INT_MAX;        // initialize n_int to max int value
    short n_short = SHRT_MAX;   // symbols defined in climits file
    long n_long = LONG_MAX;
	long long n_llong = LLONG_MAX;

    // sizeof operator yields size of type or of variable
    cout << "int is " << sizeof (int) << " bytes." << endl;
    cout << "short is " << sizeof n_short << " bytes." << endl;
    cout << "long is " << sizeof n_long << " bytes." << endl;
    cout << "long long is " << sizeof n_llong << " bytes." << endl;
    cout << endl;

    cout << "Maximum values:" << endl;
    cout << "int: " << n_int << endl;
    cout << "short: " << n_short << endl;
    cout << "long: " << n_long << endl;
    cout << "long long: " << n_llong << endl << endl;

    cout << "Minimum int value = " << INT_MIN << endl;
    cout << "Bits per byte = " << CHAR_BIT << endl;
	// cin.get();
    return 0;
}

以上代码来自c++ prime plus 案例：如何使用sizeof与

sizeof 运算符是返回类型或变量的长度，即所占字节数。

引用的头文件，可以得出整形限制的信息。

(数据类型)_MAX：用于计算该数据类型的最大取值。

（数据类型）_BIT:用于计算字节的位数。