Problem: Create a reversed copy of a string. Given "hello", produce "olleh". This tests string building and character access. Combine iteration with construction techniques. One approach: build new string by appending from end.
Start empty, loop from last index to first, append each character. Write result += s[i]; for each in reverse order. Another approach: copy string, then two-pointer swap like arrays.
Start pointers at ends, swap, move toward center. Both work. Choose based on context.