c++ - 为什么 long 和 long long 的最大值产生相同的输出？

Question

#include <iostream>
using namespace std;
#include <climits>

int main () {

    int n_int = INT_MAX;
    short n_short = SHRT_MAX;
    long n_long = LONG_MAX;
    long long n_llong = LLONG_MAX;

    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 << "llong: " << n_llong << endl << endl;
    //cout << endl;

    cout << "Minimum int value = " << INT_MIN << endl;
    cout << "Maximum int value = " << INT_MAX << endl;
    cout << "Bits per byte = " << CHAR_BIT << endl;

    return 0;
}

输出: long 和 long long 变量产生完全相同的最大值，我不确定为什么。 long值应该输出最大值2147483647。

int is 4 bytes.
short is 2 bytes.
long is 8 bytes.
long long is 8 bytes.
Maximum values:
int:   2147483647
short: 32767
long:  9223372036854775807
llong: 9223372036854775807
Minimum int value = -2147483648
Maximum int value = 2147483647
Bits per byte = 8

Answer 1

long 不保证是 32 位长；它只需 至少 32 位长。您的实现已将 long 定义为具有 64 位。请注意，尽管 long 和 long long 在您的实现中具有相同的范围，但它们仍然是不同的类型。