I'm trying to find an efficient way to take an input string and capitalize the first letter after every punctuation mark (. : ? !) which is followed by a white space.
Input:
"I ate something. but I didn't:
instead, no. what do you think? i
think not! excuse me.moi"
Output:
"I ate something. But I didn't:
Instead, no. What do you think? I
think not! Excuse me.moi"
The obvious would be to split it and then capitalize the first char of every group, then concatenate everything. But it's uber ugly. What's the best way to do this? (I'm thinking Regex.Replace using a MatchEvaluator that capitalizes the first letter but would like to get more ideas)
Thanks!
Fast and easy:
static class Ext
{
public static string CapitalizeAfter(this string s, IEnumerable<char> chars)
{
var charsHash = new HashSet<char>(chars);
StringBuilder sb = new StringBuilder(s);
for (int i = 0; i < sb.Length - 2; i++)
{
if (charsHash.Contains(sb[i]) && sb[i + 1] == ' ')
sb[i + 2] = char.ToUpper(sb[i + 2]);
}
return sb.ToString();
}
}
Usage:
string capitalized = s.CapitalizeAfter(new[] { '.', ':', '?', '!' });
Try this:
string expression = #"[\.\?\!,]\s+([a-z])";
string input = "I ate something. but I didn't: instead, no. what do you think? i think not! excuse me.moi";
char[] charArray = input.ToCharArray();
foreach (Match match in Regex.Matches(input, expression,RegexOptions.Singleline))
{
charArray[match.Groups[1].Index] = Char.ToUpper(charArray[match.Groups[1].Index]);
}
string output = new string(charArray);
// "I ate something. But I didn't: instead, No. What do you think? I think not! Excuse me.moi"
I use an extension method.
public static string CorrectTextCasing(this string text)
{
// /[.:?!]\\s[a-z]/ matches letters following a space and punctuation,
// /^(?:\\s+)?[a-z]/ matches the first letter in a string (with optional leading spaces)
Regex regexCasing = new Regex("(?:[.:?!]\\s[a-z]|^(?:\\s+)?[a-z])", RegexOptions.Multiline);
// First ensure all characters are lower case.
// (In my case it comes all in caps; this line may be omitted depending upon your needs)
text = text.ToLower();
// Capitalize each match in the regular expression, using a lambda expression
text = regexCasing.Replace(text, s => (s.Value.ToUpper));
// Return the new string.
return text;
}
Then I can do the following:
string mangled = "i'm A little teapot, short AND stout. here IS my Handle.";
string corrected = s.CorrectTextCasing();
// returns "I'm a little teapot, short and stout. Here is my handle."
Using the Regex / MatchEvaluator route, you could match on
"[.:?!]\s[a-z]"
and capitalize the entire match.
Where the text variable contains the string
string text = "I ate something. but I didn't: instead, no. what do you think? i think not! excuse me.moi";
string[] punctuators = { "?", "!", ",", "-", ":", ";", "." };
for (int i = 0; i< 7;i++)
{
int pos = text.IndexOf(punctuators[i]);
while(pos!=-1)
{
text = text.Insert(pos+2, char.ToUpper(text[pos + 2]).ToString());
text = text.Remove(pos + 3, 1);
pos = text.IndexOf(punctuators[i],pos+1);
}
}
Related
I have to convert the first letter of every word the user inputs into uppercase. I don't think I'm doing it right so it doesn't work but I'm not sure where has gone wrong D: Thank you in advance for your help! ^^
static void Main(string[] args)
{
Console.Write("Enter anything: ");
string x = Console.ReadLine();
string pattern = "^";
Regex expression = new Regex(pattern);
var regexp = new System.Text.RegularExpressions.Regex(pattern);
Match result = expression.Match(x);
Console.WriteLine(x);
foreach(var match in x)
{
Console.Write(match);
}
Console.WriteLine();
}
If your exercise isn't regex operations, there are built-in utilities to do what you are asking:
System.Globalization.TextInfo ti = System.Globalization.CultureInfo.CurrentCulture.TextInfo;
string titleString = ti.ToTitleCase("this string will be title cased");
Console.WriteLine(titleString);
Prints:
This String Will Be Title Cased
If you operation is for regex, see this previous StackOverflow answer: Sublime Text: Regex to convert Uppercase to Title Case?
First of all, your Regex "^" matches the start of a line. If you need to match each word in a multi-word line, you'll need a different Regex, e.g. "[A-Za-z]".
You're also not doing anything to actually change the first letter to upper case. Note that strings in C# are immutable (they cannot be changed after creation), so you will need to create a new string which consists of the first letter of the original string, upper cased, followed by the rest of the string. Give that part a try on your own. If you have trouble, post a new question with your attempt.
string pattern = "(?:^|(?<= ))(.)"
^ doesnt capture anything by itself.You can replace by uppercase letters by applying function to $1.See demo.
https://regex101.com/r/uE3cC4/29
I would approach this using Model Extensions.
PHP has a nice method called ucfirst.
So I translated that into C#
public static string UcFirst(this string s)
{
var stringArr = s.ToCharArray(0, s.Length);
var char1ToUpper = char.Parse(stringArr[0]
.ToString()
.ToUpper());
stringArr[0] = char1ToUpper;
return string.Join("", stringArr);
}
Usage:
[Test]
public void UcFirst()
{
string s = "john";
s = s.UcFirst();
Assert.AreEqual("John", s);
}
Obviously you would still have to split your sentence into a list and call UcFirst for each item in the list.
Google C# Model Extensions if you need help with what is going on.
One more way to do it with regex:
string input = "this string will be title cased, even if there are.cases.like.that";
string output = Regex.Replace(input, #"(?<!\w)\w", m => m.Value.ToUpper());
I hope this may help
public static string CapsFirstLetter(string inputValue)
{
char[] values = new char[inputValue.Length];
int count = 0;
foreach (char f in inputValue){
if (count == 0){
values[count] = Convert.ToChar(f.ToString().ToUpper());
}
else{
values[count] = f;
}
count++;
}
return new string(values);
}
So I've got this question.
Write a program that extracts from a text all sentences that contain a particular word.
We accept that the sentences are separated from each other by the character "." and the words are separated from one another by a character which is not a letter.
Sample text:
We are living in a yellow submarine. We don't have anything else. Inside the submarine is very tight. So we are drinking all the day. We will move out of it in 5 days.
Sample result:
We are living in a yellow submarine.
We will move out of it in 5 days.
This my code so far.
public static string Extract(string str, string keyword)
{
string[] arr = str.Split('.');
string answer = string.Empty;
foreach(string sentence in arr)
{
var iter = sentence.GetEnumerator();
while(iter.MoveNext())
{
if(iter.Current.ToString() == keyword)
answer += sentence;
}
}
return answer;
}
Well it does not work. I call it with this code:
string example = "We are living in a yellow submarine. We don't have anything else. Inside the submarine is very tight. So we are drinking all the day. We will move out of it in 5 days.";
string keyword = "in";
string answer = Extract(example, keyword);
Console.WriteLine(answer);
which does not output anything. It's probably the iterator part since I'm not familiar with iterators.
Anyhow, the hint for the question says we should use split and IndexOf methods.
sentence.GetEnumerator() is returning a CharEnumerator, so you're examining each character in each sentence. A single character will never be equal to the string "in", which is why it isn't working. You'll need to look at each word in each sentence and compare with the term you're looking for.
Try:
public static string Extract(string str, string keyword)
{
string[] arr = str.Split('.');
string answer = string.Empty;
foreach(string sentence in arr)
{
//Add any other required punctuation characters for splitting words in the sentence
string[] words = sentence.Split(new char[] { ' ', ',' });
if(words.Contains(keyword)
{
answer += sentence;
}
}
return answer;
}
Your code goes through each sentence character by character using the iterator. Unless the keyword is a single-character word (e.g. "I" or "a") there will be no match.
One way of solving this is to use LINQ to check if a sentence has the keyword, like this:
foreach(string sentence in arr)
{
if(sentence.Split(' ').Any(w => w == keyword))
answer += sentence+". ";
}
Demo on ideone.
Another approach would be using regular expressions to check for matches only on word boundaries. Note that you cannot use a plain Contains method, because doing so results in "false positives" (i.e. finding sentences where the keyword is embedded inside a longer word).
Another thing to note is the use of += for concatenation. This approach is inefficient, because many temporary throw-away objects get created. A better way of achieving the same result is using StringBuilder.
string input = "We are living in a yellow submarine. We don't have anything else. Inside the submarine is very tight. So we are drinking all the day. We will move out of it in 5 days.";
var lookup = input.Split('.')
.Select(s => s.Split().Select(w => new { w, s }))
.SelectMany(x => x)
.ToLookup(x => x.w, x => x.s);
foreach(var sentence in lookup["in"])
{
Console.WriteLine(sentence);
}
I would split the input at the periods and followed by searching each sentence for the given word.
string metin = "We are living in a yellow submarine. We don't have anything else. Inside the submarine is very tight. So we are drinking all the day. We will move out of it in 5 days.";
string[] metinDizisi = metin.Split('.');
string answer = string.Empty;
for (int i = 0; i < metinDizisi.Length; i++)
{
if (metinDizisi[i].Contains(" in "))
{
answer += metinDizisi[i];
}
}
Console.WriteLine(answer);
You can use sentence.Contains(keyword) to check if the string has the word you are looking for.
public static string Extract(string str, string keyword)
{
string[] arr = str.Split('.');
string answer = string.Empty;
foreach(string sentence in arr)
if(sentence.Contains(keyword))
answer+=sentence;
return answer;
}
You could split on the period to get a collection of sentences, then filter those with a regex containing the keyword.
var results = example.Split('.')
.Where(s => Regex.IsMatch(s, String.Format(#"\b{0}\b", keyword)));
Quick little question...
I need to count the length of a string, but WITHOUT the spaces inside of it.
E.g. for a string like "I am Bob", string.Length would return 8 (6 letters + 2 spaces).
I need a method, or something, to give me the length (or number of) just the letters (6 in the case of "I am Bob")
I have tried the following
s.Replace (" ", "");
s.Replace (" ", null);
s.Replace (" ", string.empty);
to try and get "IamBob", which I did, but it didn't solve my problem because it still counted "" as a character.
Any help?
This returns the number of non-whitespace characters:
"I am Bob".Count(c => !Char.IsWhiteSpace(c));
Demo
Char.IsWhiteSpace:
White space characters are the following Unicode characters:
Members of the SpaceSeparator category, which includes the characters SPACE (U+0020), OGHAM SPACE MARK (U+1680), MONGOLIAN VOWEL SEPARATOR (U+180E), EN QUAD (U+2000), EM QUAD (U+2001), EN SPACE (U+2002), EM SPACE (U+2003), THREE-PER-EM SPACE (U+2004), FOUR-PER-EM SPACE (U+2005), SIX-PER-EM SPACE (U+2006), FIGURE SPACE (U+2007), PUNCTUATION SPACE (U+2008), THIN SPACE (U+2009), HAIR SPACE (U+200A), NARROW NO-BREAK SPACE (U+202F), MEDIUM MATHEMATICAL SPACE (U+205F), and IDEOGRAPHIC SPACE (U+3000).
Members of the LineSeparator category, which consists solely of the LINE SEPARATOR character (U+2028).
Members of the ParagraphSeparator category, which consists solely of the PARAGRAPH SEPARATOR character (U+2029).
The characters CHARACTER TABULATION (U+0009), LINE FEED (U+000A), LINE TABULATION (U+000B), FORM FEED (U+000C), CARRIAGE RETURN (U+000D), NEXT LINE (U+0085), and NO-BREAK SPACE (U+00A0).
No. It doesn't.
string s = "I am Bob";
Console.WriteLine(s.Replace(" ", "").Length); // 6
Console.WriteLine(s.Replace(" ", null).Length); //6
Console.WriteLine(s.Replace(" ", string.Empty).Length); //6
Here is a DEMO.
But what are whitespace characters?
http://en.wikipedia.org/wiki/Whitespace_character
You probably forgot to reassign the result of Replace. Try this:
string s = "I am bob";
Console.WriteLine(s.Length); // 8
s = s.Replace(" ", "");
Console.WriteLine(s.Length); // 6
A pretty simple way is to write an extension method that will do just that- count the characters without the white spaces. Here's the code:
public static class MyExtension
{
public static int CharCountWithoutSpaces(this string str)
{
string[] arr = str.Split(' ');
string allChars = "";
foreach (string s in arr)
{
allChars += s;
}
int length = allChars.Length;
return length;
}
}
To execute, simply call the method on the string:
string yourString = "I am Bob";
int count = yourString.CharCountWithoutSpaces();
Console.WriteLine(count); //=6
Alternatively, you can split the string an way you want if you don't want to include say, periods or commas:
string[] arr = str.Split('.');
or:
string[] arr = str.Split(',');
this is fastest way:
var spaceCount = 0;
for (var i 0; i < #string.Lenght; i++)
{
if (#string[i]==" ") spaceCount++;
}
var res = #string.Lenght-spaceCount;
Your problem is probably related to Replace() method not actually changing the string, rather returning the replaced value;
string withSpaces = "I am Bob";
string withoutSpaces = withSpaces.Replace(" ","");
Console.WriteLine(withSpaces);
Console.WriteLine(withoutSpaces);
Console.WriteLine(withSpaces.Length);
Console.WriteLine(withoutSpaces.Length);
//output
//I am Bob
//IamBob
//8
//6
You can use a combination of Length and Count functions on the string object. Here is a simple example.
string sText = "This is great text";
int nSpaces = sText.Length - sText.Count(Char.IsWhiteSpace);
This will count single or multiple (consistent) spaces accurately.
Hope it helps.
I want to find number of letter "a" in only first sentence. The code below finds "a" in all sentences, but I want in only first sentence.
static void Main(string[] args)
{
string text; int k = 0;
text = "bla bla bla. something second. maybe last sentence.";
foreach (char a in text)
{
char b = 'a';
if (b == a)
{
k += 1;
}
}
Console.WriteLine("number of a in first sentence is " + k);
Console.ReadKey();
}
This will split the string into an array seperated by '.', then counts the number of 'a' char's in the first element of the array (the first sentence).
var count = Text.Split(new[] { '.', '!', '?', })[0].Count(c => c == 'a');
This example assumes a sentence is separated by a ., ? or !. If you have a decimal number in your string (e.g. 123.456), that will count as a sentence break. Breaking up a string into accurate sentences is a fairly complex exercise.
This is perhaps more verbose than what you were looking for, but hopefully it'll breed understanding as you read through it.
public static void Main()
{
//Make an array of the possible sentence enders. Doing this pattern lets us easily update
// the code later if it becomes necessary, or allows us easily to move this to an input
// parameter
string[] SentenceEnders = new string[] {"$", #"\.", #"\?", #"\!" /* Add Any Others */};
string WhatToFind = "a"; //What are we looking for? Regular Expressions Will Work Too!!!
string SentenceToCheck = "This, but not to exclude any others, is a sample."; //First example
string MultipleSentencesToCheck = #"
Is this a sentence
that breaks up
among multiple lines?
Yes!
It also has
more than one
sentence.
"; //Second Example
//This will split the input on all the enders put together(by way of joining them in [] inside a regular
// expression.
string[] SplitSentences = Regex.Split(SentenceToCheck, "[" + String.Join("", SentenceEnders) + "]", RegexOptions.IgnoreCase);
//SplitSentences is an array, with sentences on each index. The first index is the first sentence
string FirstSentence = SplitSentences[0];
//Now, split that single sentence on our matching pattern for what we should be counting
string[] SubSplitSentence = Regex.Split(FirstSentence, WhatToFind, RegexOptions.IgnoreCase);
//Now that it's split, it's split a number of times that matches how many matches we found, plus one
// (The "Left over" is the +1
int HowMany = SubSplitSentence.Length - 1;
System.Console.WriteLine(string.Format("We found, in the first sentence, {0} '{1}'.", HowMany, WhatToFind));
//Do all this again for the second example. Note that ideally, this would be in a separate function
// and you wouldn't be writing code twice, but I wanted you to see it without all the comments so you can
// compare and contrast
SplitSentences = Regex.Split(MultipleSentencesToCheck, "[" + String.Join("", SentenceEnders) + "]", RegexOptions.IgnoreCase | RegexOptions.Singleline);
SubSplitSentence = Regex.Split(SplitSentences[0], WhatToFind, RegexOptions.IgnoreCase | RegexOptions.Singleline);
HowMany = SubSplitSentence.Length - 1;
System.Console.WriteLine(string.Format("We found, in the second sentence, {0} '{1}'.", HowMany, WhatToFind));
}
Here is the output:
We found, in the first sentence, 3 'a'.
We found, in the second sentence, 4 'a'.
You didn't define "sentence", but if we assume it's always terminated by a period (.), just add this inside the loop:
if (a == '.') {
break;
}
Expand from this to support other sentence delimiters.
Simply "break" the foreach(...) loop when you encounter a "." (period)
Well, assuming you define a sentence as being ended with a '.''
Use String.IndexOf() to find the position of the first '.'. After that, searchin a SubString instead of the entire string.
find the place of the '.' in the text ( you can use split )
count the 'a' in the text from the place 0 to instance of the '.'
string SentenceToCheck = "Hi, I can wonder this situation where I can do best";
//Here I am giving several way to find this
//Using Regular Experession
int HowMany = Regex.Split(SentenceToCheck, "a", RegexOptions.IgnoreCase).Length - 1;
int i = Regex.Matches(SentenceToCheck, "a").Count;
// Simple way
int Count = SentenceToCheck.Length - SentenceToCheck.Replace("a", "").Length;
//Linq
var _lamdaCount = SentenceToCheck.ToCharArray().Where(t => t.ToString() != string.Empty)
.Select(t => t.ToString().ToUpper().Equals("A")).Count();
var _linqAIEnumareable = from _char in SentenceToCheck.ToCharArray()
where !String.IsNullOrEmpty(_char.ToString())
&& _char.ToString().ToUpper().Equals("A")
select _char;
int a =linqAIEnumareable.Count;
var _linqCount = from g in SentenceToCheck.ToCharArray()
where g.ToString().Equals("a")
select g;
int a = _linqCount.Count();
Is there a string class member function (or something else) for removing all spaces from a string? Something like Python's str.strip() ?
You could simply do:
myString = myString.Replace(" ", "");
If you want to remove all white space characters you could use Linq, even if the syntax is not very appealing for this use case:
myString = new string(myString.Where(c => !char.IsWhiteSpace(c)).ToArray());
String.Trim method removes trailing and leading white spaces. It is the functional equivalent of Python's strip method.
LINQ feels like overkill here, converting a string to a list, filtering the list, then turning it back onto a string. For removal of all white space, I would go for a regular expression. Regex.Replace(s, #"\s", ""). This is a common idiom and has probably been optimized.
If you want to remove the spaces that prepend the string or at itt's end, you might want to have a look at TrimStart() and TrimEnd() and Trim().
If you're looking to replace all whitespace in a string (not just leading and trailing whitespace) based on .NET's determination of what's whitespace or not, you could use a pretty simple LINQ query to make it work.
string whitespaceStripped = new string((from char c in someString
where !char.IsWhiteSpace(c)
select c).ToArray());
Yes, Trim.
String a = "blabla ";
var b = a.Trim(); // or TrimEnd or TrimStart
Yes, String.Trim().
var result = " a b ".Trim();
gives "a b" in result. By default all whitespace is trimmed. If you want to remove only space you need to type
var result = " a b ".Trim(' ');
If you want to remove all spaces in a string you can use string.Replace().
var result = " a b ".Replace(" ", "");
gives "ab" in result. But that is not equivalent to str.strip() in Python.
I don't know much about Python...
IF the str.strip() just removes whitespace at the start and the end then you could use str = str.Trim() in .NET... otherwise you could just str = str.Replace ( " ", "") for removing all spaces.
IF it removes all whitespace then use
str = (from c in str where !char.IsWhiteSpace(c) select c).ToString()
There are many diffrent ways, some faster then others:
public static string StripTabsAndNewlines(this string s) {
//string builder (fast)
StringBuilder sb = new StringBuilder();
for (int i = 0; i < str.Length; i++) {
if ( ! Char.IsWhiteSpace(s[i])) {
sb.Append();
}
}
return sb.tostring();
//linq (faster ?)
return new string(input.ToCharArray().Where(c => !Char.IsWhiteSpace(c)).ToArray());
//regex (slow)
return Regex.Replace(s, #"\s+", "")
}
you could use
StringVariable.Replace(" ","")
I'm surprised no one mentioned this:
String.Join("", " all manner\tof\ndifferent\twhite spaces!\n".Split())
string.Split by default splits along the characters that are char.IsWhiteSpace so this is a very similar solution to filtering those characters out by the direct use of char.IsWhiteSpace and it's a one-liner that works in pre-LINQ environments as well.
Strip spaces? Strip whitespaces? Why should it matter? It only matters if we're searching for an existing implementation, but let's not forget how fun it is to program the solution rather than search MSDN (boring).
You should be able to strip any chars from any string by using 1 of the 2 functions below.
You can remove any chars like this
static string RemoveCharsFromString(string textChars, string removeChars)
{
string tempResult = "";
foreach (char c in textChars)
{
if (!removeChars.Contains(c))
{
tempResult = tempResult + c;
}
}
return tempResult;
}
or you can enforce a character set (so to speak) like this
static string EnforceCharLimitation(string textChars, string allowChars)
{
string tempResult = "";
foreach (char c in textChars)
{
if (allowChars.Contains(c))
{
tempResult = tempResult + c;
}
}
return tempResult;
}