C++ Program to Convert String to Lowercase

Write a C++ Program to Convert String to Lowercase with an example. In this C++ program, we used for loop to traverse upTxt string characters. We used the tolower function within the loop to convert uppercase string to lowercase.

#include<iostream>
#include<string>
using namespace std;

int main()
{
	string upTxt;
	
	cout << "\nPlease Enter the String to Convert into Lowercase  =  ";
	getline(cin, upTxt);
	
	for (int i = 0; i < upTxt.length(); i++)
  	{
  		upTxt[i] = tolower(upTxt[i]);
  	}
  	
	cout<< "\nThe Given String in Lowercase = " << upTxt;
		
 	return 0;
}

The C++ has the std transform function under the algorithm file to convert uppercase string to lowercase.

#include<iostream>
#include<string>
#include<algorithm>
using namespace std;

int main()
{
	string upTxt;
	
	cout << "\nPlease Enter the String to Convert into Lowercase  =  ";
	getline(cin, upTxt);
	
	std:: transform(upTxt.begin(), upTxt.end(), upTxt.begin(), ::tolower);
  	
	cout<< "\nThe Given String in Lowercase = " << upTxt;
		
 	return 0;
}

Please Enter the String to Convert into Lowercase  =  HELLo WolLD!

The Given String in Lowercase = hello wolld!

C++ Example to Convert String to Lowercase using a While loop

#include<iostream>
#include<string>
using namespace std;

int main()
{
	string upTxt;
	int i = 0; 
	
	cout << "\nPlease Enter the String to Convert into Lowercase  =  ";
	getline(cin, upTxt);
	
	while(i < upTxt.length())
  	{
  		if(isupper(upTxt[i]))
  		{
  			upTxt[i] = tolower(upTxt[i]);
		}
  		i++;
  	}
  	
	cout<< "\nThe Given String in Lowercase = " << upTxt;
		
 	return 0;
}

Please Enter the String to Convert into Lowercase  =  TutORIAL GATEWAY

The Given String in Lowercase = tutorial gateway

In this C++ code to Convert String to Lowercase, we used the if statement to check whether the character is uppercase. If true, we are adding 32 to the ASCII Value to get the lowercase character.

#include<iostream>
#include<string>
using namespace std;

int main()
{
	string upTxt;
	
	cout << "\nPlease Enter the String to Convert into Lowercase  =  ";
	getline(cin, upTxt);
	
	for (int i = 0; i < upTxt.length(); i++)
  	{
  		if(upTxt[i] >= 'A' && upTxt[i] <= 'Z')
  		{
  			upTxt[i] = upTxt[i] + 32;
		}
  	}
  	
	cout<< "\nThe Given String in Lowercase = " << upTxt;
		
 	return 0;
}

Please Enter the String to Convert into Lowercase  =  c++ PROGRAMS

The Given String in Lowercase = c++ programs

In this C++ Convert String to Lowercase example, we used the If statement. Within the If statement, we used ASCII values to identify the uppercase characters in a string. Then, we are converting them to lowercase.

#include<iostream>
#include<string>
using namespace std;

int main()
{
	string upTxt;
	
	cout << "\nPlease Enter the String to Convert into Lowercase  =  ";
	getline(cin, upTxt);
	
	for (int i = 0; i < upTxt.length(); i++)
  	{
  		if(upTxt[i] >= 65 && upTxt[i] <= 90)
  		{
  			upTxt[i] = upTxt[i] + 32;
		}
  	}
  	
	cout<< "\nThe Given String in Lowercase = " << upTxt;
		
 	return 0;
}

Please Enter the String to Convert into Lowercase  =  HI GUYS

The Given String in Lowercase = hi guys

C++ Program to Convert String to Lowercase using Functions

#include<iostream>
#include<string>
using namespace std;

string stringLower(string upTxt)
{
	for (int i = 0; i < upTxt.length(); i++)
  	{
  		if(upTxt[i] >= 'A' && upTxt[i] <= 'Z')
  		{
  			upTxt[i] = upTxt[i] + 32;
		}
  	}
  	return upTxt;
}

int main()
{
	string upTxt;
	
	cout << "\nPlease Enter the String to Convert into Lowercase  =  ";
	getline(cin, upTxt);
	
	string lw = stringLower(upTxt);
  	
	cout<< "\nThe Given String in Lowercase = " << lw;
		
 	return 0;
}

Please Enter the String to Convert into Lowercase  =  HI 2021 GUys

The Given String in Lowercase = hi 2021 guys