C＃|字符串运算符

字符串是一个字符数组。 String类将文本表示为一系列Unicode字符，并且在.NET基类库中定义。 String类的主要用途是提供属性，运算符和方法，以使使用字符串变得容易。
String类中存在两种类型的运算符：

1. Equality(String，String)运算符
2. 不等式(String，String)运算符

Equality(String，String)运算符

该运算符用于检查给定的字符串是否包含相同的值。如果两个字符串相等，则返回true。否则，返回false。
句法：

public static bool operator == ( string x, string y );

参数：

string x: String x is the first string to compare. 
string y: String y is the second string to compare. 
 

返回值：该运算符的返回类型为System.Boolean 。如果字符串x等于y字符串返回true，否则返回false。
范例1：

CSharp

// C# program to illustrate the
// Equality operator
using System;
 
class GFG {
 
    // Main Method
    public static void Main(string[] args)
    {
         
        // variables
        string s1 = "WelcomeToGeeks";
        string s2 = "WelcomeToGeeks";
        string s3 = "Geeksforgeeks";
        bool result1, result2;
 
        // Equality operator return true
        // as both strings are equal
        result1 = s1 == s2;
        Console.WriteLine("s1 is equal to s2: {0} ", result1);
 
        // Equality operator return false
        // as both strings are not equal
        result2 = s1 == s3;
        Console.WriteLine("s1 is equal to s3: {0} ", result2);
    }
}

输出：

s1 is equal to s2: True 
s1 is equal to s3: False 

范例2：

尖锐的

// C# program to illustrate
// the Equality operator
using System;
 
class GFG {
     
    // Main method
    public static void Main()
    {
         
        // function calling
        Check("GEEKS");
        Check("geeks");
        Check("GEEKS");
    }
 
    // Function to check the
    // string for equality
    static void Check(String value)
    {
         
        // string str
        String str = "geeks";
 
        // Display the comparison between strings
        Console.WriteLine("String 1: {0}", str);
        Console.WriteLine("String 2:  {0}", value);
        Console.WriteLine("Comparison of string 1 and string 2: {0}",
                                                      str == value);
    }
}

输出：

String 1: geeks
String 2:  GEEKS
Comparison of string 1 and string 2: False
String 1: geeks
String 2:  geeks
Comparison of string 1 and string 2: True
String 1: geeks
String 2:  GEEKS
Comparison of string 1 and string 2: False

不等式(字符串，字符串)运算符

该运算符用于检查给定的字符串是否包含不同的值。如果两个字符串彼此不同，则返回true。否则，返回false。
句法：

public static bool operator != ( string x, string y );

参数：

string x: String x is the first string to compare. 
string y: String y is the second string to compare. 
 

返回值：该运算符的返回类型为System.Boolean 。如果字符串x不等于y字符串返回true，否则返回false。
下面给出了一些示例，以更好地理解实现：
范例1：

尖锐的

// C# program to illustrate the
// Inequality operator
using System;
 
class GFG {
 
    // Main Method
    public static void Main(string[] args)
    {
         
        // variables
        string s1 = "WelcomeToGeeks";
        string s2 = "WelcomeToGeeks";
        string s3 = "Geeksforgeeks";
        bool result1, result2;
 
        // Inequality operator return true
        // as both strings are different from each other
        result1 = s1 != s3;
        Console.WriteLine("s1 is different from s3: {0} ", result1);
 
        // Inequality operator return false
        // as both strings are equal
        result2 = s1 != s2;
        Console.WriteLine("s1 is different from s2: {0} ", result2);
    }
}

输出：

s1 is different from s3: True 
s1 is different from s2: False

范例2：

尖锐的

// C# program to illustrate the concept
// of Inequality operator
using System;
 
class GFG {
     
    // main method
    public static void Main()
    {
         
        // function calling
        Check("GEEKS");
        Check("geeks");
        Check("GEEKS");
    }
 
    // method to check the string value
    static void Check(String value)
    {
         
        // string str
        String str = "geeks";
 
        // Display the comparison between strings
        Console.WriteLine("string 1: {0}", str);
        Console.WriteLine("string 2:  {0}", value);
        Console.WriteLine("Comparison of string 1 and string 2: {0}",
                                                       str != value);
    }
}

输出：

string 1: geeks
string 2:  GEEKS
Comparison of string 1 and string 2: True
string 1: geeks
string 2:  geeks
Comparison of string 1 and string 2: False
string 1: geeks
string 2:  GEEKS
Comparison of string 1 and string 2: True

参考： https : //docs.microsoft.com/zh-cn/dotnet/api/system。字符串?view = netframework-4.7.2＃运算符