#include <stdio.h> #include <iostream> using namespace std; union U1 { char s[9]; //偏移为0 int n; //偏移为0 double d; //偏移为0 }; union U2 { char s[5]; int n; double d; }; int main(int argc, char *argv[]) { U1 u1; U2 u2; u1.n = 0x010203; printf("sizeof(U1) = %d\n", sizeof(U1)); printf("sizeof(U1) = %d\n", sizeof(U2)); printf("addr(u1) = 0x%x\n", &u1); printf("addr(u1.s) %% sizeof(double) = 0x%x %% %d = %d\n", &u1.s, sizeof(double), (unsigned long)(&u1.s) % (sizeof(double))); printf("addr(u1.n) %% sizeof(int) = 0x%x %% %d = %d\n", &u1.n, sizeof(int), (unsigned long)(&u1.n) % (sizeof(int))); printf("addr(u1.d) %% sizeof(char) = 0x%x %% %d = %d\n", &u1.d, sizeof(char), (unsigned long)(&u1.d) % (sizeof(char*))); printf("--------------------------------------\n"); system("pause"); return 0; }
结构体(Union)内存分配
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转载自blog.csdn.net/devin_seu/article/details/79696814
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