Files and Streams

String Writer

Build text with writer methods before reading the finished string.

streams A writer collects text through method calls instead of one long expression.

String Writer

item
StringWriterExample.cs
Replay: real traced execution (multi-file project)
using System;
using System.IO;

class Program
{
    static void Main()
    {
        string item = "tea";

        using StringWriter writer = new StringWriter();
        writer.Write("order:");
        writer.WriteLine(item);
        writer.Write("done");

        string result = writer.ToString().Replace("\n", "|").Replace("\r", "");

        Console.WriteLine($"item={item}");
        Console.WriteLine($"result={result}");
    }
}

using System;
using System.IO;

class Program
{
    static void Main()
    {
        string item = "coffee";

        using StringWriter writer = new StringWriter();
        writer.Write("order:");
        writer.WriteLine(item);
        writer.Write("done");

        string result = writer.ToString().Replace("\n", "|").Replace("\r", "");

        Console.WriteLine($"item={item}");
        Console.WriteLine($"result={result}");
    }
}

using System;
using System.IO;

class Program
{
    static void Main()
    {
        string item = "juice";

        using StringWriter writer = new StringWriter();
        writer.Write("order:");
        writer.WriteLine(item);
        writer.Write("done");

        string result = writer.ToString().Replace("\n", "|").Replace("\r", "");

        Console.WriteLine($"item={item}");
        Console.WriteLine($"result={result}");
    }
}

  1. item ← tea, writer ← (empty), result ← order:tea|done

    5{6    static void Main()7    {8        string item→ tea = "tea"; //@item="coffee", "juice"910        using StringWriter writer→ (empty) = new StringWriter();11        writer→ order:.Write("order:");12        writer→ order:tea
.WriteLine(itemtea);13        writer→ order:tea
done.Write("done");1415        string result→ order:tea|done = writerorder:tea
done.ToString().Replace("\n", "|").Replace("\r", "");1617        Console.WriteLine($"item={itemtea}");18        Console.WriteLine($"result={resultorder:tea|done}");19    }
    outputitem=tea
result=order:tea|done

  1. item ← coffee, writer ← (empty), result ← order:coffee|done

    5{6    static void Main()7    {8        string item→ coffee = "coffee";910        using StringWriter writer→ (empty) = new StringWriter();11        writer→ order:.Write("order:");12        writer→ order:coffee
.WriteLine(itemcoffee);13        writer→ order:coffee
done.Write("done");1415        string result→ order:coffee|done = writerorder:coffee
done.ToString().Replace("\n", "|").Replace("\r", "");1617        Console.WriteLine($"item={itemcoffee}");18        Console.WriteLine($"result={resultorder:coffee|done}");19    }
    outputitem=coffee
result=order:coffee|done

  1. item ← juice, writer ← (empty), result ← order:juice|done

    5{6    static void Main()7    {8        string item→ juice = "juice";910        using StringWriter writer→ (empty) = new StringWriter();11        writer→ order:.Write("order:");12        writer→ order:juice
.WriteLine(itemjuice);13        writer→ order:juice
done.Write("done");1415        string result→ order:juice|done = writerorder:juice
done.ToString().Replace("\n", "|").Replace("\r", "");1617        Console.WriteLine($"item={itemjuice}");18        Console.WriteLine($"result={resultorder:juice|done}");19    }
    outputitem=juice
result=order:juice|done