C++ 字符串转小写程序

编写一个 C++ 程序，将字符串转换为小写，并附带示例。在此 C++ 程序中，我们使用 for 循环遍历 upTxt 字符串的字符。我们在循环中使用 tolower 函数将大写字符串转换为小写。

#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;
}

该程序使用算法文件下的 std transform 函数将大写字符串转换为小写。

#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++ 使用 While 循环将字符串转换为小写的示例

#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

在此程序 代码 中，用于将字符串转换为小写，我们使用 if 语句检查字符是否为大写。如果为真，我们将 ASCII 值加 32 来获得小写字符。

#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

在此字符串转换为小写的示例中，我们使用了 If 语句。在 If 语句中，我们使用 ASCII 值来识别字符串中的大写字符。然后，我们将它们转换为小写。

#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++ 使用函数将字符串转换为小写的程序

#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