Multiline string literal in C#

You can use the @ symbol in front of a string to form a verbatim string literal:

string query = @"SELECT foo, bar
FROM table
WHERE id = 42";

You also do not have to escape special characters when you use this method, except for double quotes as shown in Jon Skeet's answer.

It's called a verbatim string literal in C#, and it's just a matter of putting @ before the literal. Not only does this allow multiple lines, but it also turns off escaping. So for example you can do:

string query = @"SELECT foo, bar
FROM table
WHERE name = 'a\b'";

This includes the line breaks (using whatever line break your source has them as) into the string, however. For SQL, that's not only harmless but probably improves the readability anywhere you see the string - but in other places it may not be required, in which case you'd either need to not use a multi-line verbatim string literal to start with, or remove them from the resulting string.

The only bit of escaping is that if you want a double quote, you have to add an extra double quote symbol:

string quote = @"Jon said, ""This will work,"" - and it did!";

As a side-note, with C# 6.0 you can now combine interpolated strings with the verbatim string literal:

string camlCondition = $@"
<Where>
    <Contains>
        <FieldRef Name='Resource'/>
        <Value Type='Text'>{(string)parameter}</Value>
    </Contains>
</Where>";

The problem with using string literal I find is that it can make your code look a bit "weird" because in order to not get spaces in the string itself, it has to be completely left aligned:

    var someString = @"The
quick
brown
fox...";

Yuck.

So the solution I like to use, which keeps everything nicely aligned with the rest of your code is:

var someString = String.Join(
    Environment.NewLine,
    "The",
    "quick",
    "brown",
    "fox...");

And of course, if you just want to logically split up lines of an SQL statement like you are and don't actually need a new line, you can always just substitute Environment.NewLine for " ".

One other gotcha to watch for is the use of string literals in string.Format. In that case you need to escape curly braces/brackets '{' and '}'.

// this would give a format exception
string.Format(@"<script> function test(x) 
      { return x * {0} } </script>", aMagicValue)
// this contrived example would work
string.Format(@"<script> function test(x) 
      {{ return x * {0} }} </script>", aMagicValue)

Multiline string literal in C#

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