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Last active November 12, 2021 17:10
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Access and manipulate an int via char array using an union. C Plus plus
#include <iostream>
int main() {
union {
unsigned int a; // 32 bit number, 4 bytes
unsigned char aa[4]; // access a's bytes as an array
a = 0xaabbccdd;
printf("a: 0x%x\n", a); // a: 0xaabbccdd
// where: aa[3]=0xaa, a[2]=0xbb, a[1]=0xcc, a[0]=0xdd
for (unsigned int i=0; i < 4; i++) {
printf("a[%d]: 0x%x\n", i, (unsigned int) aa[i]);
printf("a: 0x%x\n", a);
return 0;
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gubatron commented Nov 12, 2021

$ g++ int_as_array.cpp && ./a.out
a: 0xaabbccdd
a[0]: 0xdd
a[1]: 0xcc
a[2]: 0xbb
a[3]: 0xaa
a: 0xaabbccff

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