C#数据类型：string简单使用

string cmdstr = "Helloworld!";
cmdstr = cmdstr.Remove(cmdstr.Length - 1);//删除最后一个字符

//字符串连接
string str1 = "Hello";
string str2 = "World";
string result1 = str1 + " " + str2;
string result2 = $"{str1} {str2}";//建议使用干方式连接字符

//字符串长度
string str = "Hello";
int length = str.Length;

//字符串插入
string str = "HelloWorld";
string result = str.Insert(5, ", ");
Console.WriteLine(result); // 输出: Hello, World

//字符串删除
string str = "Hello, World!";
string result = str.Remove(5, 2);
Console.WriteLine(result); // 输出: Hello World!

//字符串复制
string str = "Hello";
string copy = string.Copy(str);
Console.WriteLine(copy); // 输出: Hello

//字符串格式化日期
DateTime date = DateTime.Now;
string formattedDate = date.ToString("yyyy-MM-dd HH:mm:ss");
Console.WriteLine(formattedDate); // 输出: 当前日期和时间的格式化字符串

//字符串比较
string str1 = "Hello";
string str2 = "hello";
bool isEqual = string.Equals(str1, str2, StringComparison.OrdinalIgnoreCase);

//字符串查找
string str = "Hello, World!";
int index = str.IndexOf("World");

//字符串替换
string str = "Hello, World!";
string result = str.Replace("World", "C#");

//字符串分割
string str = "Hello,World,C#";
string[] parts = str.Split(',');
foreach (var part in parts)
{
Console.WriteLine(part); // 输出: Hello, World, C#
}

//字符串截取
string str = "Hello, World!";
string result = str.Substring(7, 5);
Console.WriteLine(result); // 输出: World

//字符串转小写
string str = "HELLO, WORLD!";
string lowerCase = str.ToLower();
Console.WriteLine(lowerCase); // 输出: hello, world!

//字符串转大写
string str = "hello, world!";
string upperCase = str.ToUpper();
Console.WriteLine(upperCase); // 输出: HELLO, WORLD!

//字符串修剪
string str = "   Hello, World!   ";
string trimmed = str.Trim();
Console.WriteLine(trimmed); // 输出: Hello, World!

//字符串格式化
string name = "Alice";
int age = 30;
string result = string.Format("Name: {0}, Age: {1}", name, age);
Console.WriteLine(result); // 输出: Name: Alice, Age: 30

//字符串拼接
List<string> words = new List<string> { "Hello", "World", "C#" };
string result = string.Join(", ", words);
Console.WriteLine(result); // 输出: Hello, World, C#

//字符串是否为空或空字符串
string str1 = "";
string str2 = null;
bool isNullOrEmpty1 = string.IsNullOrEmpty(str1);
bool isNullOrEmpty2 = string.IsNullOrEmpty(str2);
Console.WriteLine(isNullOrEmpty1); // 输出: True
Console.IsNullOrWhiteSpace(isNullOrEmpty2); // 输出: True

//字符串编码转换
string str = "Hello, 世界!";
byte[] bytes = System.Text.Encoding.UTF8.GetBytes(str);
string result = System.Text.Encoding.UTF8.GetString(bytes);
Console.WriteLine(result); // 输出: Hello, 世界!

//字符串反转
string str = "Hello";
char[] charArray = str.ToCharArray();
Array.Reverse(charArray);
string result = new string(charArray);
Console.WriteLine(result); // 输出: olleH