Search Results

Search found 35523 results on 1421 pages for 'nullable string'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 3/1421 | < Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

  • Shortest Common Superstring: find shortest string that contains all given string fragments

    - by occulus
    Given some string fragments, I would like to find the shortest possible single string ("output string") that contains all the fragments. Fragments can overlap each other in the output string. Example: For the string fragments: BCDA AGF ABC The following output string contains all fragments, and was made by naive appending: BCDAAGFABC However this output string is better (shorter), as it employs overlaps: ABCDAGF ^ ABC ^ BCDA ^ AGF I'm looking for algorithms for this problem. It's not absolutely important to find the strictly shortest output string, but the shorter the better. I'm looking for an algorithm better than the obvious naive one that would try appending all permutations of the input fragments and removing overlaps (which would appear to be NP-Complete). I've started work on a solution and it's proving quite interesting; I'd like to see what other people might come up with. I'll add my work-in-progress to this question in a while.

    Read the article

  • String contains string in objective-c (iphone)

    - by Jonathan
    How can I check if a string (NSString) contains another smaller string? I was hoping for something like: NSString *string = @"hello bla bla"; NSLog(@"%d",[string containsSubstring:@"hello"]); But the closest I could find was: if ([string rangeOfString:@"hello"] == 0) { NSLog(@sub string doesnt exist") } else { NSLog(@"exists") } I typed that straight into stack so sorry if there are errors, but there would be if I was doing it in Xcode so you don't need to point any out. Anyway is that the best way to find if a string contains another string.

    Read the article

  • Nullable ToString()

    - by StupidDeveloper
    I see everywhere constructions like: int? myVar = null; string test = myVar.HasValue ? myVar.Value.ToString() : string.Empty; Why not use simply: string test = myVar.ToString(); Isn't that exactly the same ? At least Reflector says that: public override string ToString() { if (!this.HasValue) { return ""; } return this.value.ToString(); } So, is that correct (the shorter version) or am I missing something?

    Read the article

  • LINQ-to-SQL IN/Contains() for Nullable<T>

    - by Craig Walker
    I want to generate this SQL statement in LINQ: select * from Foo where Value in ( 1, 2, 3 ) The tricky bit seems to be that Value is a column that allows nulls. The equivalent LINQ code would seem to be: IEnumerable<Foo> foos = MyDataContext.Foos; IEnumerable<int> values = GetMyValues(); var myFoos = from foo in foos where values.Contains(foo.Value) select foo; This, of course, doesn't compile, since foo.Value is an int? and values is typed to int. I've tried this: IEnumerable<Foo> foos = MyDataContext.Foos; IEnumerable<int> values = GetMyValues(); IEnumerable<int?> nullables = values.Select( value => new Nullable<int>(value)); var myFoos = from foo in foos where nullables.Contains(foo.Value) select foo; ...and this: IEnumerable<Foo> foos = MyDataContext.Foos; IEnumerable<int> values = GetMyValues(); var myFoos = from foo in foos where values.Contains(foo.Value.Value) select foo; Both of these versions give me the results I expect, but they do not generate the SQL I want. It appears that they're generating full-table results and then doing the Contains() filtering in-memory (ie: in plain LINQ, without -to-SQL); there's no IN clause in the DataContext log. Is there a way to generate a SQL IN for Nullable types?

    Read the article

  • sample java code for approximate string matching or boyer-moore extended for approximate string matc

    - by Dolphin
    Hi I need to find 1.mismatch(incorrectly played notes), 2.insertion(additional played), & 3.deletion (missed notes), in a music piece (e.g. note pitches [string values] stored in a table) against a reference music piece. This is either possible through exact string matching algorithms or dynamic programming/ approximate string matching algos. However I realised that approximate string matching is more appropriate for my problem due to identifying mismatch, insertion, deletion of notes. Or an extended version of Boyer-moore to support approx. string matching. Is there any link for sample java code I can try out approximate string matching? I find complex explanations and equations - but I hope I could do well with some sample code and simple explanations. Or can I find any sample java code on boyer-moore extended for approx. string matching? I understand the boyer-moore concept, but having troubles with adjusting it to support approx. string matching (i.e. to support mismatch, insertion, deletion). Also what is the most efficient approx. string matching algorithm (like boyer-moore in exact string matching algo)? Greatly appreciate any insight/ suggestions. Many thanks in advance

    Read the article

  • Why isnt this returning the new string?

    - by Evan Kimia
    I have a recursive method that reversed a string (HW assignment, has to be recursive). I did it....but its only returning the value of the string after the first pass. By analyzing the output after each pass i can see it does do its job correctly. heres my code, and the output i get below it: String s = "Hello, I love you wont you tell me your name?"; int k=0; public String reverseThisString(String s) { if(k!=s.length()) { String first =s.substring(0,k)+s.charAt(s.length()-1); String end = ""+s.substring(k, s.length()-1); k++; s=first+end; System.out.println(s); this.reverseThisString(s); } return s; } output: ?Hello, I love you wont you tell me your name

    Read the article

  • WPF Toolkit: Nullable object must have a value

    - by Via Lactea
    Hi All, I am trying to create some line charts from a dataset and getting an error (WPF+WPF Toolkit + C#): Nullable object must have a value Here is a code that I use to add some data points to the chart: ObservableCollection points = new ObservableCollection(); foreach (DataRow dr in dc.Tables[0].Rows) { points.Add(new VelChartPoint() { Label = dr[0].ToString(), Value = double.Parse(dr[1].ToString()) }); } Here is a class VelChartPoint public class VelChartPoint : VelObject, INotifyPropertyChanged { public DateTime Date { get; set; } public string Label { get; set; } private double _Value; public double Value { get { return _Value; } set { _Value = value; var handler = PropertyChanged; if (null != handler) { handler.Invoke(this, new PropertyChangedEventArgs("Value")); } } } public string FieldName { get; set; } public event PropertyChangedEventHandler PropertyChanged; public VelChartPoint() { } } So the problem occures in this part of the code points.Add(new VelChartPoint { Name = dc.Tables[0].Rows[0][0].ToString(), Value = double.Parse(dc.Tables[0].Rows[0][1].ToString()) } ); I've made some tests, here are some results i've found out. This part of code does'nt work for me: string[] labels = new string[] { "label1", "label2", "label3" }; foreach (string label in labels) { points.Add(new VelChartPoint { Name = label, Value = 500.0 } ); } But this one works fine: points.Add(new VelChartPoint { Name = "LabelText", Value = double.Parse(dc.Tables[0].Rows[0][1].ToString()) } ); Please, help me to solve this error.

    Read the article

  • C: evaluate part of the string

    - by Halst
    I cant find an expression to evaluate a part of a string. I want to get something like that: if (string[4:8]=='abc') {...} I started writing like this: if (string[4]=='a' && string[5]=='b' && string[6]=='c') {...} but if i need to evaluate a big part of string like if (string[10:40] == another_string) {...} then it gets to write TOO much expressions. Are there any ready-to-use solutions?

    Read the article

  • Nullable<T> as a parameter

    - by ferch
    I alredy have this: public static object GetDBValue(object ObjectEvaluated) { if (ObjectEvaluated == null) return DBNull.Value; else return ObjectEvaluated; } used like: List<SqlParameter> Params = new List<SqlParameter>(); Params.Add(new SqlParameter("@EntityType", GetDBValue(EntityType))); Now i wanted to keep the same interface but extend that to use it with nullable public static object GetDBValue(int? ObjectEvaluated) { if (ObjectEvaluated.HasValue) return ObjectEvaluated.Value; else return DBNull.Value; } public static object GetDBValue(DateTime? ObjectEvaluated) {...} but i want only 1 function GetDBValue for nullables. How do I do that and keep the call as is is? Is that possible at all? I can make it work like: public static object GetDBValue<T>(Nullable<T> ObjectEvaluated) where T : struct { if (ObjectEvaluated.HasValue) return ObjectEvaluated.Value; else return DBNull.Value; } But the call changes to: Params.Add(new SqlParameter("@EntityID ", GetDBValue<int>(EntityID)));

    Read the article

  • Setting Nullable Integer to String Containing Nothing yields 0

    - by Brian MacKay
    I've been pulling my hair out over some unexpected behavior from nullable integers. If I set an Integer to Nothing, it becomes Nothing as expected. If I set an Integer? to a String that is Nothing, it becomes 0! Of course I get this whether I explicitly cast the String to Integer? or not. I realize I could work around this pretty easily but I want to know what I'm missing. Dim NullString As String = Nothing Dim NullableInt As Integer? = CType(NullString, Integer?) 'Expected NullableInt to be Nothing, but it's 0! NullableInt = Nothing 'This works -- NullableInt now contains Nothing. How is this EDIT: Previously I had my code up here so without the explicit conversion to 'Integer?' and everyone seemed to be fixated on that. I want to be clear that this is not an issue that would have been caught by Option Strict On -- check out the accepted answer. This is a quirk of the string-to-integer conversion rules which predate nullable types, but still impact them.

    Read the article

  • How to fill a section within c++ string?

    - by stacker
    Having a string of whitespaces: string *str = new string(); str->resize(width,' '); I'd like to fill length chars at a position. In C it would look like memset(&str[pos],'#', length ); How can i achieve this with c++ string, I tried string& assign( const string& str, size_type index, size_type len ); but this seems to truncat the original string. Is there an easy C++ way to do this? Thanks.

    Read the article

  • C# String.Replace with a start/index (Added my (slow) implementation)

    - by Chris T
    I'd like an efficient method that would work something like this EDIT: Sorry I didn't put what I'd tried before. I updated the example now. // Method signature, Only replaces first instance or how many are specified in max public int MyReplace(ref string source,string org, string replace, int start, int max) { int ret = 0; int len = replace.Length; int olen = org.Length; for(int i = 0; i < max; i++) { // Find the next instance of the search string int x = source.IndexOf(org, ret + olen); if(x > ret) ret = x; else break; // Insert the replacement source = source.Insert(x, replace); // And remove the original source = source.Remove(x + len, olen); // removes original string } return ret; } string source = "The cat can fly but only if he is the cat in the hat"; int i = MyReplace(ref source,"cat", "giraffe", 8, 1); // Results in the string "The cat can fly but only if he is the giraffe in the hat" // i contains the index of the first letter of "giraffe" in the new string The only reason I'm asking is because my implementation I'd imagine getting slow with 1,000s of replaces.

    Read the article

  • Javascript string replace with calculations

    - by Chris
    Is there a way to resolve mathematical expressions in strings in javascript? For example, suppose I want to produce the string "Tom has 2 apples, Lucy has 3 apples. Together they have 5 apples" but I want to be able to substitute in the variables. I can do this with a string replacement: string = "Tom has X apples, Lucy has Y apples. Together they have Z apples"; string2 = string.replace(/X/, '2').replace(/Y/, '3').replace(/Z/, '5'); However, it would be better if, instead of having a variable Z, I could use X+Y. Now, I could also do a string replace for X+Y and replace it with the correct value, but that would become messy when trying to deal with all the possible in-string calculations I might want to do. I suppose I'm looking for a way to achieve this: string = "Something [X], something [Y]. Something [(X+Y^2)/5X]"; And for the [_] parts to be understood as expressions to be resolved before substituting back into the string. Thanks for your help.

    Read the article

  • Java String.indexOf and empty Strings

    - by tmeisenh
    I'm curious why the String.indexOf is returning a 0 (instead of -1) when asking for the index of an empty string within a string. The Javadocs only say this method returns the index in this String of the specified string, -1 if the string isn't found. System.out.println("FOO".indexOf("")); // outputs 0 wtf!!! System.out.println("FOO".indexOf("bar")); // outputs -1 as expected System.out.println("FOO".indexOf("F")); // outputs 0 as expected System.out.println("".indexOf("")); // outputs 0 as expected, I think

    Read the article

  • Using string.Format for simple things?

    - by Gerrie Schenck
    In my early .Net programming days, I used string.Format() only for complex string concatenations, for example to compile strings as Problem with customer order 234 of date 2/2/2002 and payment id 55543. But now I use string.Format for almost every string concatenation I have to do, also simple ones such as prefixing a string with something. Console.WriteLine(string.Format("\t\t{0}", myString)); Is there any possible overhead on this? Maybe I should use the regular + operator to do these simple operations? What's your opinion on this?

    Read the article

  • Split String in C# without delimiter (sort of)

    - by Zach
    Hi, I want to split a string in C#.NET that looks like this: string Letters = "hello"; and put each letter (h, e, l, l, o) into an array or ArrayList. I have no idea what to use as the delimiter in String.Split(delimiter). I can do it if the original string has commas (or anything else): string Letters = "H,e,l,l,o"; string[] AllLettersArray = Letters.Split(",".ToCharArray()); But I have no idea what to use in a case with (supposedly) no delimiter. Is there a special character like Environment.Newline? Thanks.

    Read the article

  • Performance surprise with "as" and nullable types

    - by Jon Skeet
    I'm just revising chapter 4 of C# in Depth which deals with nullable types, and I'm adding a section about using the "as" operator, which allows you to write: object o = ...; int? x = o as int?; if (x.HasValue) { ... // Use x.Value in here } I thought this was really neat, and that it could improve performance over the C# 1 equivalent, using "is" followed by a cast - after all, this way we only need to ask for dynamic type checking once, and then a simple value check. This appears not to be the case, however. I've included a sample test app below, which basically sums all the integers within an object array - but the array contains a lot of null references and string references as well as boxed integers. The benchmark measures the code you'd have to use in C# 1, the code using the "as" operator, and just for kicks a LINQ solution. To my astonishment, the C# 1 code is 20 times faster in this case - and even the LINQ code (which I'd have expected to be slower, given the iterators involved) beats the "as" code. Is the .NET implementation of isinst for nullable types just really slow? Is it the additional unbox.any that causes the problem? Is there another explanation for this? At the moment it feels like I'm going to have to include a warning against using this in performance sensitive situations... Results: Cast: 10000000 : 121 As: 10000000 : 2211 LINQ: 10000000 : 2143 Code: using System; using System.Diagnostics; using System.Linq; class Test { const int Size = 30000000; static void Main() { object[] values = new object[Size]; for (int i = 0; i < Size - 2; i += 3) { values[i] = null; values[i+1] = ""; values[i+2] = 1; } FindSumWithCast(values); FindSumWithAs(values); FindSumWithLinq(values); } static void FindSumWithCast(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = 0; foreach (object o in values) { if (o is int) { int x = (int) o; sum += x; } } sw.Stop(); Console.WriteLine("Cast: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } static void FindSumWithAs(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = 0; foreach (object o in values) { int? x = o as int?; if (x.HasValue) { sum += x.Value; } } sw.Stop(); Console.WriteLine("As: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } static void FindSumWithLinq(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = values.OfType<int>().Sum(); sw.Stop(); Console.WriteLine("LINQ: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } }

    Read the article

  • Parse string to create a list of element

    - by Nick
    I have a string like this: "\r color=\"red\" name=\"Jon\" \t\n depth=\"8.26\" " And I want to parse this string and create a std::list of this object: class data { std::string name; std::string value; }; Where for example: name = color value = red What is the fastest way? I can use boost. EDIT: This is what i've tried: vector<string> tokens; split(tokens, str, is_any_of(" \t\f\v\n\r")); if(tokens.size() > 1) { list<data> attr; for_each(tokens.begin(), tokens.end(), [&attr](const string& token) { if(token.empty() || !contains(token, "=")) return; vector<string> tokens; split(tokens, token, is_any_of("=")); erase_all(tokens[1], "\""); attr.push_back(data(tokens[0], tokens[1])); } ); } But it does not work if there are spaces inside " ": like color="red 1".

    Read the article

  • Using nullable types in C#

    - by Martin Brown
    I'm just interested in people's opinions. When using nullable types in C# what is the best practice way to test for null: bool isNull = (i == null); or bool isNull = !i.HasValue; Also when assigning to a non-null type is this: long? i = 1; long j = (long)i; better than: long? i = 1; long j = i.Value;

    Read the article

  • Binding a nullable int to an asp:TextBox

    - by Slauma
    I have a property int? MyProperty as a member in my datasource (ObjectDataSource). Can I bind this to a TextBox, like <asp:TextBox ID="MyTextBox" runat="server" Text='<%# Bind("MyProperty") %>' /> Basically I want to get a null value displayed as blank "" in the TextBox, and a number as a number. If the TextBox is blank MyProperty shall be set to null. If the TextBox has a number in it, MyProperty should be set to this number. If I try it I get an exception: "Blank is not a valid Int32". But how can I do that? How to work with nullable properties and Bind? Thanks in advance!

    Read the article

  • Why String.replaceAll() don't work on this String ?

    - by Aloong
    //This source is a line read from a file String src = "23570006,music,**,wu(),1,exam,\"Monday9,10(H2-301)\",1-10,score,"; //This sohuld be from a matcher.group() when Pattern.compile("\".*?\"") String group = "\"Monday9,10(H2-301)\""; src = src.replaceAll("\"", ""); group = group.replaceAll("\"", ""); String replacement = group.replaceAll(",", "#@"); System.out.println(src.contains(group)); src = src.replaceAll(group, replacement); System.out.println(group); System.out.println(replacement); System.out.println(src); I'm trying to replace the "," between \"s so I can ues String.split() latter. But the above just not working , the result is: true Monday9,10(H2-301) Monday9#@10(H2-301) 23570006,music,**,wu(),1,exam,Monday9,10(H2-301),1-10,score, but when I change the src string to String src = "123\"9,10\"123"; String group = "\"9,10\""; It works well true 9,10 9#@10 1239#@10123 What's the matter with the string???

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >