How to cut off leading digits? C++

Question

How can I cut off the leading digits of a number in order to only display the last two digits, without using the library. For example:

1923 to 23

2001 to 01

1234 to 34

123 to 23

with only

#include <iomanip>
#include <iostream>

Thanks!

Answer 1

If your numbers are in int form (rather than string form), you should think about using the modulo operator.

If the numbers are in char[] form, there is an easy solution that involves indexing into the string, like:

char *myString = "ABCDE";
int lengthOfMyString = 5;
cout << myString[lengthOfMyString - 3]
     << myString[lengthOfMyString - 5]
     << myString[lengthOfMyString - 4];
//outputs the word CAB

Answer 2

If you're just working with integers I'd suggest just doing mod %100 for simplicity:

int num =2341;

cout << num%100;

Would display 41.

And if you need a leading zero just do:

std::cout << std::setw(2) << std::setfill('0') << num%100 << std::endl;