السلاسل والنصوص: عدم القابلية للتغيير والاستيفاء والحرفية وStringBuilder والمقارنة

نظرة عامة على النص

عدم قابلية التغيير

using System;

public class Program
{
  public static void Main(string[] args)
  {
    string s = "hello";
    string upper = s.ToUpper();           // new string
    Console.WriteLine("s = " + s);        // hello
    Console.WriteLine("upper = " + upper);// HELLO

    string replaced = s.Replace("h", "y"); // new string
    Console.WriteLine("replaced = " + replaced);
  }
}

الاستيفاء ومحارف الهروب

using System;

public class Program
{
  public static void Main(string[] args)
  {
    string name = "Ada";
    int score = 95;

    // C# 6 string interpolation and escapes
    string msg = $"Hi {name}, score = {score}";
    string quoted = "She said \"hi\"";
    string line = "first line\nsecond line";

    Console.WriteLine(msg);
    Console.WriteLine(quoted);
    Console.WriteLine(line);
  }
}

السلاسل النصية الحرفية

using System;

public class Program
{
  public static void Main(string[] args)
  {
    // Verbatim string keeps backslashes and newlines as typed
    string path = @"C:\Projects\Demo\readme.txt";
    string multi = @"Line1
Line2";
    Console.WriteLine(path);
    Console.WriteLine(multi);
  }
}

StringBuilder

using System;
using System.Text;

public class Program
{
  public static void Main(string[] args)
  {
    var sb = new StringBuilder();
    for (int i = 1; i <= 3; i = i + 1)
    {
      sb.Append("Item ").Append(i).Append(", ");
    }
    string result = sb.ToString();
    Console.WriteLine(result);
  }
}

المقارنة والثقافة؛ char

using System;
using System.Globalization;

public class Program
{
  public static void Main(string[] args)
  {
    string a = "file";
    string b = "FILE";

    // Case-insensitive, culture-invariant comparison
    bool same = string.Equals(a, b, StringComparison.OrdinalIgnoreCase);
    Console.WriteLine("Same (ord ignore case) = " + same);

    // Culture example: ToUpper with current culture
    string iDot = "i";
    string upper = iDot.ToUpper(CultureInfo.CurrentCulture);
    Console.WriteLine("Upper(i) in current culture = " + upper);

  }
}

معنى عدم قابلية التغيير

خلاصة