I am trying to get the input from the user in a single Line with with [, ,] separators. Like this:
[Q,W,1] [R,T,3] [Y,U,9]
And then I will use these inputs in a function like this:
f.MyFunction('Q','W',1); // Third parameter will be taken as integer
f.MyFunction('R','T',3);
f.MyFunction('Y','U',9);
I thought I could do sth like:
string input = Console.ReadLine();
string input1 = input.Split(' ')[0];
char input2 = input.Trim(',') [0];
But it seems to repeat a lot.
What would be the most logical way to do this?
Sometimes a regular expression really is the best tool for the job. Use a pattern that matches the input pattern and use Regex.Matches to extract all the possible inputs:
var funcArgRE = new Regex(#"\[(.),(.),(\d+)\]", RegexOptions.Compiled);
foreach (Match match in funcArgRE.Matches(input)) {
var g = match.Groups;
f.MyFunction(g[1].Value[0], g[2].Value[0], Int32.Parse(g[3].Value));
}
Well, you could use LinQ to objects functions and do something like this:
var inputs = input.Split(' ')
.Select(x =>
x.Replace("[", "")
.Replace("]", ""))
.Select(x => new UserInput(x))
.ToList();
foreach(var userInput in inputs)
{
f.MyFunction(userInput.A, userInput.B, userInput.Number);
}
// Somewhere else
public record UserInput
{
public UserInput(string input)
{
//Do some kind of validation here and throw exception accordingly
var parts = input.Split(',');
A = parts[0][0];
B = parts[1][0];
Number = Convert.ToInt32(parts[2]);
}
public char A { get; init; }
public char B { get; init; }
public int Number { get; init; }
};
Or you could go further and implement "operator overloading" for the UserInput record and make it possible to implicitly convert from string to UserInput
Related
I am trying to select an element in array, that matches something in a string.
For example:
string[] splitChar = new string[] { "+=", "-=" };
string content = "5+=2";
So i want to check if content, contains something from splitChar, and if it does then select the value so it can be assigned to a string variable.
Lambdas and LINQ would be overkill for this. You can just do a simple foreach:
string match = "";
foreach (var str in splitChar)
{
if (content.Contains(str))
{
match = str;
break;
}
}
if (!String.IsNullOrEmpty(match))
{
// Do whatever with `match`
}
If you really wanted to use LINQ, though, FirstOrDefault would be your best bet:
string match = splitChar.FirstOrDefault(s => content.Contains(s));
if (!String.IsNullOrEmpty(match))
{
// Do whatever with `match`
}
Have you tried checking with FirstOrDefault like the following?
string[] splitChar = new string[] { "+=", "-=" };
string content = "5+=2";
var stringPresent = splitChar.FirstOrDefault(x=>content.Contains(x));
if(String.IsNullOrEmpty(stringPresent))
Console.WriteLine("Not found");
else
Console.WriteLine(stringPresent);
Check this Example
I need to find two strings within a list that contains the characters from another string, which are not in order. To make it clear, an example could be a list of animals like:
lion
dog
bear
cat
And a given string is: oodilgn.
The answer here would be: lion and dog
Each character from the string will be used only once.
Is there a regular expression that will allow me to do this?
You could try to put the given string between []. These brackets will allow choosing - in any order - from these letters only. This may not be a perfect solution, but it will catch the majority of your list.
For example, you could write oodilgn as [oodilgn], then add a minimum number of letters to be found - let's say 3 - by using the curly brackets {}. The full regex will be like this:
[oodilgn]{3,}
This code basically says: find any word that has three of the letters that are located between brackets in any order.
Demo: https://regex101.com/r/MCWHjQ/2
Here is some example algorithm that does the job. I have assumed that the two strings together don't need to take all letters from the text else i make additional commented check. Also i return first two appropriate answers.
Here is how you call it in the outside function, Main or else:
static void Main(string[] args)
{
var text = "oodilgn";
var listOfWords = new List<string> { "lion", "dog", "bear", "cat" };
ExtractWordsWithSameLetters(text, listOfWords);
}
Here is the function with the algorithm. All string manuplations are entirely with regex.
public static void ExtractWordsWithSameLetters(string text, List<string> listOfWords)
{
string firstWord = null;
string secondWord = null;
for (var i = 0; i < listOfWords.Count - 1; i++)
{
var textCopy = text;
var firstWordIsMatched = true;
foreach (var letter in listOfWords[i])
{
var pattern = $"(.*?)({letter})(.*?)";
var regex = new Regex(pattern);
if (regex.IsMatch(text))
{
textCopy = regex.Replace(textCopy, "$1*$3", 1);
}
else
{
firstWordIsMatched = false;
break;
}
}
if (!firstWordIsMatched)
{
continue;
}
firstWord = listOfWords[i];
for (var j = i + 1; j < listOfWords.Count; j++)
{
var secondWordIsMatched = true;
foreach (var letter in listOfWords[j])
{
var pattern = $"(.*?)({letter})(.*?)";
var regex = new Regex(pattern);
if (regex.IsMatch(text))
{
textCopy = regex.Replace(textCopy, "$1*$3", 1);
}
else
{
secondWordIsMatched = false;
break;
}
}
if (secondWordIsMatched)
{
secondWord = listOfWords[j];
break;
}
}
if (secondWord == null)
{
firstWord = null;
}
else
{
//if (textCopy.ToCharArray().Any(l => l != '*'))
//{
// break;
//}
break;
}
}
if (firstWord != null)
{
Console.WriteLine($"{firstWord} { secondWord}");
}
}
Function is far from optimised but does what you want. If you want to return results, not print them just create an array and stuff firstWord and secondWord in it and have return type string[] or add two paramaters with ref out In those cases you will need to check the result in the calling function.
please try this out
Regex r=new Regex("^[.*oodilgn]$");
var list=new List<String>(){"lion","dog","fish","god"};
var output=list.Where(x=>r.IsMatch(x));
result
output=["lion","dog","god"];
I would like to retrieve values in string formatted like this :
public var any:int = 0;
public var anyId:Number = 2;
public var theEnd:Vector.<uint>;
public var test:Boolean = false;
public var others1:Vector.<int>;
public var firstValue:CustomType;
public var field2:Boolean = false;
public var secondValue:String = "";
public var isWorks:Boolean = false;
I want to store field name, type and value in a custom class Property :
public class Property
{
public string Name { get; set; }
public string Type { get; set; }
public string Value { get; set; }
}
And with a Regex expression get these values.
How can I do ?
Thanks
EDIT : I tried this but I don't know how to go further with vectors..etc
/public var ([a-zA-Z0-9]*):([a-zA-Z0-9]*)( = \"?([a-zA-Z0-9]*)\"?)?;/g
Ok, posting my regex-based answer.
Your regex - /public var ([a-zA-Z0-9]*):([a-zA-Z0-9]*)( = \"?([a-zA-Z0-9]*)\"?)?;/g - contains regex delimiters, and they are not supported in C#, and thus are treated as literal symbols. You need to remove them and the modifier g since to obtain multiple matches in C# Regex.Matches, or Regex.Match with while and Match.Success/.NextMatch() can be used.
The regex I am using is (?<=\s*var\s*)(?<name>[^=:\n]+):(?<type>[^;=\n]+)(?:=(?<value>[^;\n]+))?. The newline symbols are included as negated character classes can match a newline character.
var str = "public var any:int = 0;\r\npublic var anyId:Number = 2;\r\npublic var theEnd:Vector.<uint>;\r\npublic var test:Boolean = false;\r\npublic var others1:Vector.<int>;\r\npublic var firstValue:CustomType;\r\npublic var field2:Boolean = false;\r\npublic var secondValue:String = \"\";\r\npublic var isWorks:Boolean = false;";
var rx = new Regex(#"(?<=\s*var\s*)(?<name>[^=:\n]+):(?<type>[^;=\n]+)(?:=(?<value>[^;\n]+))?");
var coll = rx.Matches(str);
var props = new List<Property>();
foreach (Match m in coll)
props.Add(new Property(m.Groups["name"].Value,m.Groups["type"].Value, m.Groups["value"].Value));
foreach (var item in props)
Console.WriteLine("Name = " + item.Name + ", Type = " + item.Type + ", Value = " + item.Value);
Or with LINQ:
var props = rx.Matches(str)
.OfType<Match>()
.Select(m =>
new Property(m.Groups["name"].Value,
m.Groups["type"].Value,
m.Groups["value"].Value))
.ToList();
And the class example:
public class Property
{
public string Name { get; set; }
public string Type { get; set; }
public string Value { get; set; }
public Property()
{}
public Property(string n, string t, string v)
{
this.Name = n;
this.Type = t;
this.Value = v;
}
}
NOTE ON PERFORMANCE:
The regex is not the quickest, but it certainly beats the one in the other answer. Here is a test performed at regexhero.net:
It seems, that you don't want regular expressions; in a simple case
as you've provided:
String text =
#"public var any:int = 0;
public var anyId:Number = 2;
public var theEnd:Vector.<uint>;
public var test:Boolean = false;
public var others1:Vector.<int>;
public var firstValue:CustomType;
public var field2:Boolean = false;";
List<Property> result = text
.Split(new Char[] {'\r','\n'}, StringSplitOptions.RemoveEmptyEntries)
.Select(line => {
int varIndex = line.IndexOf("var") + "var".Length;
int columnIndex = line.IndexOf(":") + ":".Length;
int equalsIndex = line.IndexOf("="); // + "=".Length;
// '=' can be absent
equalsIndex = equalsIndex < 0 ? line.Length : equalsIndex + "=".Length;
return new Property() {
Name = line.Substring(varIndex, columnIndex - varIndex - 1).Trim(),
Type = line.Substring(columnIndex, columnIndex - varIndex - 1).Trim(),
Value = line.Substring(equalsIndex).Trim(' ', ';')
};
})
.ToList();
if text can contain comments and other staff, e.g.
"public (*var is commented out*) var sample: int = 123;;;; // another comment"
you have to implement a parser
You can use the following pattern:
\s*(?<vis>\w+?)\s+var\s+(?<name>\w+?)\s*:\s*(?<type>\S+?)(\s*=\s*(?<value>\S+?))?\s*;
to match each element in a line. Appending ? after a quantifier results in a non-greedy match which makes the pattern a lot simpler - no need to negate all unwanted classes.
Values are optional, so the value group is wrapped in another, optional group (\s*=\s*(?<value>\S+?))?
Using the RegexOptions.Multiline option means we don't have to worry about accidentally matching newlines.
The C# 6 syntax in the following example isn't required, but multiline string literals and interpolated strings make for much cleaner code.
var input= #"public var any:int = 0;
public var anyId:Number = 2;
public var theEnd:Vector.<uint>;
public var test:Boolean = false;
public var others1:Vector.<int>;
public var firstValue:CustomType;
public var field2:Boolean = false;
public var secondValue:String = """";
public var isWorks:Boolean = false;";
var pattern= #"\s*(?<vis>\w+?)\s+var\s+(?<name>\w+?)\s*:\s*(?<type>\S+?)(\s*=\s*(?<value>\S+?))?\s*;"
var regex = new Regex(pattern, RegexOptions.Multiline);
var results=regex.Matches(input);
foreach (Match m in results)
{
var g = m.Groups;
Console.WriteLine($"{g["name"],-15} {g["type"],-10} {g["value"],-10}");
}
var properties = (from m in results.OfType<Match>()
let g = m.Groups
select new Property
{
Name = g["name"].Value,
Type = g.["type"].Value,
Value = g["value"].Value
})
.ToList();
I would consider using a parser generator like ANTLR though, if I had to parse more complex input or if there are multiple patterns to match. Learning how to write the grammar takes some time, but once you learn it, it's easy to create parsers that can match input that would require very complicated regular expressions. Whitespace management also becomes a lot easier
In this case, the grammar could be something like:
property : visibility var name COLON type (EQUALS value)? SEMICOLON;
visibility : ALPHA+;
var : ALPHA ALPHA ALPHA;
name : ALPHANUM+;
type : (ALPHANUM|DOT|LEFT|RIGHT);
value : ALPHANUM
| literal;
literal : DOUBLE_QUOTE ALPHANUM* DOUBLE_QUOTE;
ALPHANUM : ALPHA
| DIGIT;
ALPHA : [A-Z][a-z];
DIGIT : [0-9];
...
WS : [\r\n\s] -> skip;
With a parser, adding eg comments would be as simple as adding comment before SEMICOLON in the property rule and a new comment rule that would match the pattern of a comment
I have searched a lot to find a solution to this, but could not find anything. I do however suspect that it is because I don't know what to search for.
First, I have a string that I convert to an array. The string will be formatted like so:
"99.28099822998047,68.375 118.30699729919434,57.625 126.49999713897705,37.875 113.94499683380127,11.048999786376953 96.00499725341797,8.5"
I create the array with the following code:
public static Array StringToArray(string String)
{
var list = new List<string>();
string[] Coords = String.Split(' ', ',');
foreach (string Coord in Coords)
{
list.Add(Coord);
}
var array = list.ToArray();
return array;
}
Now my problem is; I am trying to find a way to convert it back into a string, with the same formatting. So, I could create a string simply using:
public static String ArrayToString(Array array)
{
string String = string.Join(",", array);
return String;
}
and then hopefully replace every 2nd "," with a space (" "). Is this possible? Or are there a whole other way you would do this?
Thank you in advance! I hope my question makes sense.
There is no built-in way of doing what you need. However, it's pretty trivial to achieve what it is you need e.g.
public static string[] StringToArray(string str)
{
return str.Replace(" ", ",").Split(',');
}
public static string ArrayToString(string[] array)
{
StringBuilder sb = new StringBuilder();
for (int i = 0; i <= array.Length-1; i++)
{
sb.AppendFormat(i % 2 != 0 ? "{0} " : "{0},", array[i]);
}
return sb.ToString();
}
If those are pairs of coordinates, you can start by parsing them like pairs, not like separate numbers:
public static IEnumerable<string[]> ParseCoordinates(string input)
{
return input.Split(' ').Select(vector => vector.Split(','));
}
It is easier then to reconstruct the original string:
public static string PrintCoordinates(IEnumerable<string[]> coords)
{
return String.Join(" ", coords.Select(vector => String.Join(",", vector)));
}
But if you absolutely need to have your data in a flat structure like array, it is then possible to convert it to a more structured format:
public static IEnumerable<string[]> Pairwise(string[] coords)
{
coords.Zip(coords.Skip(1), (coord1, coord2) => new[] { coord1, coord2 });
}
You then can use this method in conjunction with PrintCoordinates to reconstruct your initial string.
Here is a route to do it. I don't think other solutions were removing last comma or space. I also include a test.
public static String ArrayToString(Array array)
{
var useComma = true;
var stringBuilder = new StringBuilder();
foreach (var value in array)
{
if (useComma)
{
stringBuilder.AppendFormat("{0}{1}", value, ",");
}
else
{
stringBuilder.AppendFormat("{0}{1}", value, " ");
}
useComma = !useComma;
}
// Remove last space or comma
stringBuilder.Length = stringBuilder.Length - 1;
return stringBuilder.ToString();
}
[TestMethod]
public void ArrayToStringTest()
{
var expectedStringValue =
"99.28099822998047,68.375 118.30699729919434,57.625 126.49999713897705,37.875 113.94499683380127,11.048999786376953 96.00499725341797,8.5";
var array = new[]
{
"99.28099822998047",
"68.375",
"118.30699729919434",
"57.625",
"126.49999713897705",
"37.875",
"113.94499683380127",
"11.048999786376953",
"96.00499725341797",
"8.5",
};
var actualStringValue = ArrayToString(array);
Assert.AreEqual(expectedStringValue, actualStringValue);
}
Another way of doing it:
string inputString = "1.11,11.3 2.22,12.4 2.55,12.8";
List<string[]> splitted = inputString.Split(' ').Select(a => a.Split(',')).ToList();
string joined = string.Join(" ", splitted.Select(a => string.Join(",",a)).ToArray());
"splitted" list will look like this:
1.11 11.3
2.22 12.4
2.55 12.8
"joined" string is the same as "inputString"
Here's another approach to this problem.
public static string ArrayToString(string[] array)
{
Debug.Assert(array.Length % 2 == 0, "Array is not dividable by two.");
// Group all coordinates as pairs of two.
int index = 0;
var coordinates = from item in array
group item by index++ / 2
into pair
select pair;
// Format each coordinate pair with a comma.
var formattedCoordinates = coordinates.Select(i => string.Join(",", i));
// Now concatinate all the pairs with a space.
return string.Join(" ", formattedCoordinates);
}
And a simple demonstration:
public static void A_Simple_Test()
{
string expected = "1,2 3,4";
string[] array = new string[] { "1", "2", "3", "4" };
Debug.Assert(expected == ArrayToString(array));
}
When I need to stringify some values by joining them with commas, I do, for example:
string.Format("{0},{1},{3}", item.Id, item.Name, item.Count);
And have, for example, "12,Apple,20".
Then I want to do opposite operation, get values from given string. Something like:
parseFromString(str, out item.Id, out item.Name, out item.Count);
I know, it is possible in C. But I don't know such function in C#.
Yes, this is easy enough. You just use the String.Split method to split the string on every comma.
For example:
string myString = "12,Apple,20";
string[] subStrings = myString.Split(',');
foreach (string str in subStrings)
{
Console.WriteLine(str);
}
Possible implementations would use String.Split or Regex.Match
example.
public void parseFromString(string input, out int id, out string name, out int count)
{
var split = input.Split(',');
if(split.length == 3) // perhaps more validation here
{
id = int.Parse(split[0]);
name = split[1];
count = int.Parse(split[2]);
}
}
or
public void parseFromString(string input, out int id, out string name, out int count)
{
var r = new Regex(#"(\d+),(\w+),(\d+)", RegexOptions.IgnoreCase);
var match = r.Match(input);
if(match.Success)
{
id = int.Parse(match.Groups[1].Value);
name = match.Groups[2].Value;
count = int.Parse(match.Groups[3].Value);
}
}
Edit: Finally, SO has a bunch of thread on scanf implementation in C#
Looking for C# equivalent of scanf
how do I do sscanf in c#
If you can assume the strings format, especially that item.Name does not contain a ,
void parseFromString(string str, out int id, out string name, out int count)
{
string[] parts = str.split(',');
id = int.Parse(parts[0]);
name = parts[1];
count = int.Parse(parts[2]);
}
This will simply do what you want but I would suggest you add some error checking. Better still consider serializing/deserializing to XML or JSON.
Use Split function
var result = "12,Apple,20".Split(',');