how to put an unsigned int into a char array and extract it back
bit-manipulation, c, c++, memcpy
Solution
When you declare test on line 12 `unsigned int tested;` it should be initialized to zero `unsigned int tested =0;` Also, compiling with -Wuninitialized or -Wall would have warned you tested was uninitialized.
Problem
can someone explain why this isn't working? i am trying to put an unsigned int into a char buffer and then fetch it back into another unsigned int. ``` 1 #include<stdio.h> 2 #include<string.h> 3 int main(){ 4 unsigned int tester = 320; 5 char buffer[512]; 6 memset(buffer,0,512); 7 memcpy(buffer,&tester,sizeof(unsigned int)); 8 /*buffer[0]|=tester; 9 buffer[1]|=(tester>>8); 10 buffer[2]|=(tester>>16); 11 buffer[3]|=(tester>>24);*/ 12 unsigned int tested; 13 memcpy(&tested,buffer,sizeof(unsigned int)); 14 15 /*tested|=(buffer[3]<<24); 16 tested|=(buffer[2]<<16); 17 tested|=(buffer[1]<<8); 18 tested|=(buffer[0]);*/ 19 printf("\n %d\n",tested); 20 } ``` when i do memcpy it works. but when i take the bitwise approach it doesn't work. funny thing is when i put buffer size as 20 it works. but when i use large buffers, or even 50, it always prints 368 in the bitwise appraoch. again the memcpy works fine.