How to insert newline in string literal?

ぃ、小莉子 提交于 2019-11-28 03:02:52
Jon Skeet

Well, simple options are:

  • string.Format:

    string x = string.Format("first line{0}second line", Environment.NewLine);
    
  • String concatenation:

    string x = "first line" + Environment.NewLine + "second line";
    
  • String interpolation (in C#6 and above):

    string x = $"first line{Environment.NewLine}second line";
    

You could also use \n everywhere, and replace:

string x = "first line\nsecond line\nthird line".Replace("\n",
                                                         Environment.NewLine);

Note that you can't make this a string constant, because the value of Environment.NewLine will only be available at execution time.

If you want a const string that contains Environment.NewLine in it you can do something like this:

const string stringWithNewLine =
@"first line
second line
third line";

EDIT

Since this is in a const string it is done in compile time therefore it is the compiler's interpretation of a newline. I can't seem to find a reference explaining this behavior but, I can prove it works as intended. I compiled this code on both Windows and Ubuntu (with Mono) then disassembled and these are the results:

As you can see, in Windows newlines are interpreted as \r\n and on Ubuntu as \n

var sb = new StringBuilder();
sb.Append(first);
sb.AppendLine(); // which is equal to Append(Environment.NewLine);
sb.Append(second);
return sb.ToString();
MajesticRa

One more way of convenient placement of Environment.NewLine in format string. The idea is to create string extension method that formats string as usual but also replaces {nl} in text with Environment.NewLine

Usage

   " X={0} {nl} Y={1}{nl} X+Y={2}".FormatIt(1, 2, 1+2);
   gives:
    X=1
    Y=2
    X+Y=3

Code

    ///<summary>
    /// Use "string".FormatIt(...) instead of string.Format("string, ...)
    /// Use {nl} in text to insert Environment.NewLine 
    ///</summary>
    ///<exception cref="ArgumentNullException">If format is null</exception>
    [StringFormatMethod("format")]
    public static string FormatIt(this string format, params object[] args)
    {
        if (format == null) throw new ArgumentNullException("format");

        return string.Format(format.Replace("{nl}", Environment.NewLine), args);
    }

Note

  1. If you want ReSharper to highlight your parameters, add attribute to the method above

    [StringFormatMethod("format")]

  2. This implementation is obviously less efficient than just String.Format

  3. Maybe one, who interested in this question would be interested in the next question too: Named string formatting in C#

string myText =
    @"<div class=""firstLine""></div>
      <div class=""secondLine""></div>
      <div class=""thirdLine""></div>";

that's not it:

string myText =
@"<div class=\"firstLine\"></div>
  <div class=\"secondLine\"></div>
  <div class=\"thirdLine\"></div>";
static class MyClass
{
   public const string NewLine="\n";
}

string x = "first line" + MyClass.NewLine + "second line"

newer .net versions allow you to use $ in front of the literal which allows you to use variables inside like follows:

var x = $"Line 1{Environment.NewLine}Line 2{Environment.NewLine}Line 3";

If you really want the New Line string as a constant, then you can do this:

public readonly string myVar = Environment.NewLine;

The user of the readonly keyword in C# means that this variable can only be assigned to once. You can find the documentation on it here. It allows the declaration of a constant variable whose value isn't known until execution time.

I like more the "pythonic way"

List<string> lines = new List<string> {
    "line1",
    "line2",
    String.Format("{0} - {1} | {2}", 
        someVar,
        othervar, 
        thirdVar
    )
};

if(foo)
    lines.Add("line3");

return String.Join(Environment.NewLine, lines);

If I understand the question: Couple "\r\n" to get that new line below in a textbox. My example worked -

string s1 = comboBox1.Text; // s1 is the variable assigned to box 1, etc. string s2 = comboBox2.Text;

string both = s1 + "\r\n" + s2; textBox1.Text = both; A typical answer could be s1 s2 in the text box using defined type style.

If you are working with Web application you can try this.

StringBuilder sb = new StringBuilder();
sb.AppendLine("Some text with line one");
sb.AppendLine("Some mpre text with line two");
MyLabel.Text = sb.ToString().Replace(Environment.NewLine, "<br />")

Here, Environment.NewLine doesn't worked.

I put a "<br/>" in a string and worked.

Ex:

ltrYourLiteral.Text = "First line.<br/>Second Line.";

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