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Outputting c# console application to webpage [duplicate]

Is there an easy way to create a multiline string literal in C#?
Here's what I have now:
string query = "SELECT foo, bar"
+ " FROM table"
+ " WHERE id = 42";
I know PHP has
<<<BLOCK
BLOCK;
Does C# have something similar?

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)

Why do people keep confusing strings with string literals? The accepted answer is a great answer to a different question; not to this one.
I know this is an old topic, but I came here with possibly the same question as the OP, and it is frustrating to see how people keep misreading it. Or maybe I am misreading it, I don't know.
Roughly speaking, a string is a region of computer memory that, during the execution of a program, contains a sequence of bytes that can be mapped to text characters. A string literal, on the other hand, is a piece of source code, not yet compiled, that represents the value used to initialize a string later on, during the execution of the program in which it appears.
In C#, the statement...
string query = "SELECT foo, bar"
+ " FROM table"
+ " WHERE id = 42";
... does not produce a three-line string but a one liner; the concatenation of three strings (each initialized from a different literal) none of which contains a new-line modifier.
What the OP seems to be asking -at least what I would be asking with those words- is not how to introduce, in the compiled string, line breaks that mimick those found in the source code, but how to break up for clarity a long, single line of text in the source code without introducing breaks in the compiled string. And without requiring an extended execution time, spent joining the multiple substrings coming from the source code. Like the trailing backslashes within a multiline string literal in javascript or C++.
Suggesting the use of verbatim strings, nevermind StringBuilders, String.Joins or even nested functions with string reversals and what not, makes me think that people are not really understanding the question. Or maybe I do not understand it.
As far as I know, C# does not (at least in the paleolithic version I am still using, from the previous decade) have a feature to cleanly produce multiline string literals that can be resolved during compilation rather than execution.
Maybe current versions do support it, but I thought I'd share the difference I perceive between strings and string literals.
UPDATE:
(From MeowCat2012's comment) You can. The "+" approach by OP is the best. According to spec the optimization is guaranteed: http://stackoverflow.com/a/288802/9399618

Add multiple lines : use #
string query = #"SELECT foo, bar
FROM table
WHERE id = 42";
Add String Values to the middle : use $
string text ="beer";
string query = $"SELECT foo {text} bar ";
Multiple line string Add Values to the middle: use $#
string text ="Customer";
string query = $#"SELECT foo, bar
FROM {text}Table
WHERE id = 42";

You can use # and "".
string sourse = #"{
""items"":[
{
""itemId"":0,
""name"":""item0""
},
{
""itemId"":1,
""name"":""item1""
}
]
}";

In C# 11 [2022], you will be able to use Raw String literals.
The use of Raw String Literals makes it easier to use " characters without having to write escape sequences.
Solution for OP:
string query1 = """
SELECT foo, bar
FROM table
WHERE id = 42
""";
string query2 = """
SELECT foo, bar
FROM table
WHERE id = 42
and name = 'zoo'
and type = 'oversized "jumbo" grand'
""";
More details about Raw String Literals
See the Raw String Literals GitHub Issue for full details; and Blog article C# 11 Preview Updates – Raw string literals, UTF-8 and more!

I haven't seen this, so I will post it here (if you are interested in passing a string you can do this as well.) The idea is that you can break the string up on multiple lines and add your own content (also on multiple lines) in any way you wish. Here "tableName" can be passed into the string.
private string createTableQuery = "";
void createTable(string tableName)
{
createTableQuery = #"CREATE TABLE IF NOT EXISTS
["+ tableName + #"] (
[ID] INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
[Key] NVARCHAR(2048) NULL,
[Value] VARCHAR(2048) NULL
)";
}

Yes, you can split a string out onto multiple lines without introducing newlines into the actual string, but it aint pretty:
string s = $#"This string{
string.Empty} contains no newlines{
string.Empty} even though it is spread onto{
string.Empty} multiple lines.";
The trick is to introduce code that evaluates to empty, and that code may contain newlines without affecting the output. I adapted this approach from this answer to a similar question.
There is apparently some confusion as to what the question is, but there are two hints that what we want here is a string literal not containing any newline characters, whose definition spans multiple lines. (in the comments he says so, and "here's what I have" shows code that does not create a string with newlines in it)
This unit test shows the intent:
[TestMethod]
public void StringLiteralDoesNotContainSpaces()
{
string query = "hi"
+ "there";
Assert.AreEqual("hithere", query);
}
Change the above definition of query so that it is one string literal, instead of the concatenation of two string literals which may or may not be optimized into one by the compiler.
The C++ approach would be to end each line with a backslash, causing the newline character to be escaped and not appear in the output. Unfortunately, there is still then the issue that each line after the first must be left aligned in order to not add additional whitespace to the result.
There is only one option that does not rely on compiler optimizations that might not happen, which is to put your definition on one line. If you want to rely on compiler optimizations, the + you already have is great; you don't have to left-align the string, you don't get newlines in the result, and it's just one operation, no function calls, to expect optimization on.

If you don't want spaces/newlines, string addition seems to work:
var myString = String.Format(
"hello " +
"world" +
" i am {0}" +
" and I like {1}.",
animalType,
animalPreferenceType
);
// hello world i am a pony and I like other ponies.
You can run the above here if you like.

using System;
namespace Demo {
class Program {
static void Main(string[] args) {
string str = #"Welcome User,
Kindly wait for the image to
load";
Console.WriteLine(str);
}
}
}
Output
Welcome User,
Kindly wait for the image to
load

string.replace not working for me

I have this code:
string encodedKeywordsQueryValue = HttpUtility.UrlEncode(HttpContext.Current.Request.QueryString["keywords"]);
query = query.Replace(HttpContext.Current.Request.QueryString["keywords"], encodedKeywordsQueryValue);
where
HttpContext.Current.Request.QueryString["keywords"] = "abc& abc"
and
encodedKeywordsQueryValue=abc%26+abc
My old string value is not getting replaced with new one.
Can anyone suggest me to do this? I have tried combination of remove and insert methods of string but not getting desired results.
Kindly help me with this.

HttpContext.Current.Request.QueryString["keywords"]="abc& abc" and
encodedKeywordsQueryValue=abc%26+abc
reading the documentation of replace method would tell you that it does not know about URL encoding and does not care - it is a string method. So, work on unencoded strings. There is no like style behavior - it is an exact "match and replace".
I would suggest you make a unit test for this behavior and then work out how you would like it to be - then you could for example also make a post here that is somehow baseline useful because it would have an exact example of which behavior does not work, not some riddle for us to solve.

you should have an exact string on the left side of replace. it doesn't act like 'LIKE'. see the example below:
string str1 = "abc";
string str2 = "abc&def";
str2.replace("d", str1);
result will be:
abc&abcef
hope it helps

Split string at semicolon get second part only

I have a string in the following format:
message:action
How can I parse this string and get the second part only?
The action might be different the first part will always be the same: message:
Is this a correct way?
string value="message:action";
string[] result = value.Split(':');
string action = result[1];

Yes it is. Or, since the first part is always the same, you could simply use substring:
value.SubString(8);

That solution is fine, but it's a little more work than necessary. If you know that the string will always start with "message:", why not just do this:
var action = value.Substring(8);
However, if the string that comes before the : might change, but you still only care about what comes after it, you could do this:
var action = value.Substring(value.IndexOf(':') + 1);

Yes, your solution will work. However, if the first part is always the same, another possibility is to use Substring as pswg's answer mentions.

If you know that the string will start with message: you can do this:
String value="message:action";
String result = value.Replace("message:","");

It's OK, although if you worry about there being colons in the content (e.g., "message:action:do this"):
string value="message:action";
string[] result = value.Split(':');
string action = value.Substring(result[0].Length);
(this is of course if it's not always starting with "message:")

If you want to have self-documenting code, you can use regex (so you don't think in the future, what the heck is this code and why do I take second part).
string value = "message:action";
string action = Regex.Match(value, "(?<=^message:).*").Value; // will throw exception in case if someday format changes

I'm adding one more answer for legibility. There are several correct answers in the thread so far.
Just to offer a very readable alternative at very little cost of performance consider the following:
string value = "message:action";
string action = value.Split(':').Skip(1);

C# string masking/formatting/filtering with or without regex

Hopefully this isn't too complicated, I just can't seem to find the answer I need.
I have a string with variables in, such as: this is a %variable% string
The format of the variables within the string is arbitrary, although in this example we're using the filter %{0}%
I am wanting to match variable names to properties and ideally I don't want to loop through GetProperties, formatting and testing each name. What I'd like to do is obtain "variable" as a string and test that.
I already use RegEx to get a list of the variables in a string, using the given filter:
string regExSyntax = string.Format(syntax, #"(?<word>\w+)");
but this returns them WITH the '%' (e.g. '%variable%') and as I said, that filter is arbitrary so I can't just do a string.Replace.
This feels like it should be straight-forward....
Thanks!

"(?<word>\w+)"
Is just capturing anything alphnumeric and putting it into a named capturing group called "Word"
You might be interested in learning about lookbehind and lookahead. For example:
"(?<=%)(?<word>\w+)(?=%)"
You can make it a bit more generic with putting your filter in a seperate variable:
string Boundie = "%";
string Expression = #"(?<=" + Boundie + #")(?<word>\w+)(?=" + Boundie + #")";
I hope this is anywhere near what you are looking for.

Given that your regex syntax is: string regExSyntax = string.Format(syntax, #"(?<word>\w+)");, I assume you're then going to create a Regex and use it to match against some string:
Regex reExtractVars = new Regex(regExSyntax);
Match m = reExtractVars.Match(inputString);
while (m.Success)
{
// get the matched variable
string wholeVar = m.Value; // returns "%variable%"
// get just the "word"
string wordOnly = m.Groups["word"].Value; // returns "variable"
m = m.NextMatch();
}
Or have I completely misunderstood the problem?

Acron,
If you're going to roll-your own script parser... apart from being "a bit mad", unless that's the point of the exercise (is it?), then I strongly suggest that you KISS it... Keep It Simple Stoopid.
So what denotes a VARIABLE in your scripting syntax? Is it the percent signs? And they're fixed, yes? So %name% is a variable, but #comment# is NOT a variable... correct? The phrase "that filter is arbitrary" has me worried. What's a "filter"?
If this isn't homework then just use an existing scripting engine, with existing, well defined, well known syntax. Something like Jint, for example.
Cheers. Keith.

how to get a String with String.Format to execute?

I have a little chunk of code (see below) that is returning the string:
string.Format("{0}----{1}",3,"test 2");
so how do I get this to actually "Execute"? To run and do the format/replacement of {0} and {1}?
My Code snippet:
StringBuilder sb = new StringBuilder();
sb.Append("{0}----{1}\",");
sb.AppendFormat(ReturnParamValue(siDTO, "siDTO.SuggestionItemID,siDTO.Title"));
string sbStr = "=string.Format(\""+sb.ToString()+");";
yes, ReturnParamValue gives the actually value of the DTO.
Anyways, I've taken a look at the following (but it doesn't say how to execute it:
How to get String.Format not to parse {0}
Maybe, I just should put my code snippet in a method. But, what then?

Why are you including String.Format in the string itself?
If you're looking for a generic "let me evaluate this arbitrary expression I've built up in a string" then there isn't a simple answer.
If, instead, you're looking at how to provide the parameters to the string from a function call, then you've got yourself all twisted up and working too hard.
Try something like this, based on your original code:
string result
= string.Format(
"{0}----{1}",
ReturnParamValue(siDTO, "siDTO.SuggestionItemID,siDTO.Title"));
Though, this won't entirely work since your original code seems to be only providing a single value, and you have two values in your format string - the {0} will be replaced with the value from your function, and {1} left unchanged.
What output are you expecting?
Does your ReturnParamValue() function try to return both the label and the value in a single string? If it does, and if they're comma separated, then you could try this:
var value = ReturnParamValue(siDTO, "siDTO.SuggestionItemID,siDTO.Title"));
var pieces = string.Split(',');
string result
= string.Format( "{0}----{1}", pieces[0], pieces[1]);
Though this is seriously working too hard if ReturnParamValue() is a method you control.
Update Fri 6 August
Check out the declaration for string.Format() as shown on MSDN:
public static string Format(
string format,
params Object[] args
)
Unlike the special casing you might have seen in C for printf(), there's nothing special or unusual about the way string.Format() handles multiple parameters. The key is the params keyword, which asks the compiler to provide a little "syntactic sugar" where it combines the parameters into an array for you.
Key here is that the wrapping doesn't happen if you're already passing a single object[] - so if you wanted to, you could do something like this:
object[] parameters
= ReturnParamValues(siDTO, "siDTO.SuggestionItemID,siDTO.Title");
string result
= string.Format("{0}----{1}----{2}", parameters);
Though, if I saw something like this in any codebase I maintained, I'd be treating it as a code-smell and looking for a better way to solve the problem.
Just because it's possible doesn't mean it's advisable. YMMV, of course.

I don't think you can execute it. Java is not really a interpreted language.
You may make use of scripting languages (which can even embed in your Java app as I know, start from JDK6) for such purpose, like Groovy

You could use RegEx to parse the three parameters out of the string, and then pass them to a real, actual string.Format method :-)

It looks like what you want is something like this:
string sbStr = string.Format("{0}----{1}", siDTO.SuggestionItemID, siDTO.Title);

Maybe i didn't understand your question completely, but it sounds like you need to format a format-string. If that's true you could maybe try something like this:
int width = 5;
string format = String.Format("{{0,{0}}}----{{1,{0}}}", width);
string result = String.Format(format, "ab", "cd");
So the trick is simply to escape the { or } by using a double {{ or }}.