COMPARE()

This member of the std::string class is used to lexicographically (dictionary order) compare the contents of two strings and returns an integer indicating their relative order. Specifically, it returns 0 if the strings are equal, a negative value if the calling string is less than the argument string, and a positive value if it is greater. This function can compare the entire string or specified substrings, providing a flexible way to check equality or ordering without directly using relational operators. It is widely used in sorting, searching, and string validation operations.

string1.compare(string2);
 
 * string1 is the caller, and string2 is the string it is being compared to.
 * returns 0 if strings are equal, < 0 if the caller is less, and > 0 if the caller 
   is greater.
 * the comparison is based on ASCII values of characters from left to right; the first 
   unmatched character decides the result.
    - ASCII (American Standard Code for Information Interchange) assigns a numeric 
      value to each character (e.g., 'A' = 65, 'a' = 97).

#include <iostream>
using namespace std;

int main() 
{
  string a = "mango";  // First string
  string b = "manga";  // Second string to compare

  // Compare the two strings lexicographically
  // They match until the last character: 'o' in "mango" vs 'a' in "manga"
  // Since 'o' > 'a' in ASCII, the result is positive
  int result = a.compare(b);  // Returns 14 ('o' - 'a' = 111 - 97)

  // Show the comparison result
  cout << "Comparison result: " << result << endl;  // Output: 14

  return 0;
}