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C++ program to check if the string is in lowercase using class

Submitted by Shubh Pachori, on September 06, 2022

Problem statement

Given a string, we have to check if the string is in lowercase using the class and object approach.

Example:

Input:
Enter String: SHUBH

Output:
String is not in lowercase!

C++ code to check if the string is in lowercase using the class and object approach

#include <iostream>
using namespace std;

// create a class
class String {
  // private data member
 private:
  char str[30];

  // public member functions
 public:
  // getString() function to store string
  void getString() {
    cout << "Enter String: ";
    cin.getline(str, 30);
  }

  // isLowercase() function to check 
  // if the string is in lowercase
  void isLowercase() {
    // initializing int type variables 
    // to perform operations
    int index, check = 0;

    // for loop to traverse the whole string
    for (index = 0; str[index]; index++) {
      // if condition to check if the character at 
      // index is alphabet or not
      if ((str[index] >= 'A' && str[index] <= 'Z') ||
          (str[index] >= 'a' && str[index] <= 'z') || (str[index] == 32)) {
        // if condition to check if the character at 
        // index is in lowercase or not
        if ((str[index] >= 'a' && str[index] <= 'z') || (str[index] == 32)) {
          check++;
        } else {
          check = 0;
          break;
        }
      } else {
        check = 0;
        break;
      }
    }

    if (check != 0) {
      cout << "String is in lowercase!" << endl;
    } else {
      cout << "String is not in lowercase!" << endl;
    }
  }
};

int main() {
  // create an object
  String S;

  // calling getString() function 
  // to insert string
  S.getString();

  // calling isLowercase() function to 
  // check the string
  S.isLowercase();

  return 0;
}

Output

RUN 1:
Enter String: hello world
String is in lowercase!

RUN 2:
Enter String: includehelp
String is in lowercase!

Explanation

In the above code, we have created a class String, one char type array data member str[30] to store the string, and public member functions getString() and isLowercase() to store the string and to check if the string is in lowercase or not.

In the main() function, we are creating an object S of class String, reading a string by the user using the function getString(), and finally calling the isLowercase() member function to check the string if it is in lowercase or not. The isLowercase() function contains the logic to check if the string is in lowercase or not and printing the result.

C++ Class and Object Programs (Set 2) »