I was recently asked to compare the functionality of atoi() and std::stringstream.
Here’s the code:
#include <stdio.h>
#include <stdlib.h>
#include <sstream>
void strToInt(const char* str) {
{
// Set to garbage value.
int val = 479894;
std::stringstream stream;
stream << str;
stream >> std::dec >> val;
printf("stream: '%s' -> %d\n", str, val);
}
{
const int val = atoi(str);
printf("atoi: '%s' -> %d\n", str, val);
}
printf("\n");
}
int main() {
strToInt("");
strToInt("0");
strToInt("a");
strToInt("1");
strToInt("44a");
strToInt("a44");
return 0;
}
And here’s the output:
stream: '' -> 479894 atoi: '' -> 0 stream: '0' -> 0 atoi: '0' -> 0 stream: 'a' -> 0 atoi: 'a' -> 0 stream: '1' -> 1 atoi: '1' -> 1 stream: '44a' -> 44 atoi: '44a' -> 44 stream: 'a44' -> 0 atoi: 'a44' -> 0
So it looks like the functionality of both is actually very similar (though note std::stringstream has many ways to modify its behaviour); unfortunately it seems the stream doesn’t set the result to zero when given an empty string.