I have a question about duplicating a 0-terminated string:
const char * str = "Hello World !";
size_t getSize = strlen(str);
char * temp = new char[getSize + 1];
... i know i can use this function
memcpy(temp, str, getSize);
but i want to use my own copy function which have action like this
int Count = 0;
while (str[Count] != '\0') {
temp[Count] = str[Count];
Count++;
}
both way's are true and success. now i want to check it on 10 milions times and for memcpy do this action
const char * str = "Hello World !";
size_t getSize = strlen(str);
for (size_t i = 0; i < 10000000; i++) {
char * temp = new char[getSize + 1];
memcpy(temp, str, getSize);
}
and this is for my own way
const char * str = "Hello World !";
size_t getSize = strlen(str);
for (size_t i = 0; i < 10000000; i++) {
char * temp = new char[getSize + 1];
int Count = 0;
while (str[Count] != '\0') {
temp[Count] = str[Count];
Count++;
}
}
first process done in 420 miliseconds and second done in 650 miliseconds ... why? both of those ways are same ! i want to use my own function not memcpy. is there any way to make my own way faster (fast as memcpy is fast or maybe faster)? how can i update my own way (while) to make it faster or equal with memcpy?
full source
int main() {
const char * str = "Hello world !";
size_t getSize = strlen(str);
auto start_t = chrono::high_resolution_clock::now();
for (size_t i = 0; i < 10000000; i++) {
char * temp = new char[getSize + 1];
memcpy(temp, str, getSize);
}
cout << chrono::duration_cast<chrono::milliseconds>(chrono::high_resolution_clock::now() - start_t).count() << " milliseconds\n";
start_t = chrono::high_resolution_clock::now();
for (size_t i = 0; i < 10000000; i++) {
char * temp = new char[getSize + 1];
int done = 0;
while (str[done] != '\0') {
temp[done] = str[done];
done++;
}
}
cout << chrono::duration_cast<chrono::milliseconds>(chrono::high_resolution_clock::now() - start_t).count() << " milliseconds\n";
return 0;
}
results:
482 milliseconds
654 milliseconds
