Trim c что это

Trim c что это

C# Trim() is a string method. This method is used to removes all leading and trailing white-space characters from the current String object. This method can be overloaded by passing arguments to it.

Syntax:

Explanation : First method will not take any parameter and the second method will take an array of Unicode characters or null as a parameter. Null is because of params keyword. The type of Trim() method is System.String.

Note: If no parameter is pass in public string Trim() then Null , TAB, Carriage Return and White Space will automatically remove if they are present in current string object. And If any parameter will pass into the Trim() method then only specified character(which passed as arguments in Trim() method) will be removed from the current string object. Null, TAB, Carriage Return, and White Space will not remove automatically if they are not specified in the arguments list.

Below are the programs to demonstrate the above method :

Example 1: Program to demonstrate the public string Trim() method. The Trim method removes all leading and trailing white-space characters from the current string object. Each leading and trailing trim operation stops when a non-white-space character is encountered. For example, If current string is ” abc xyz ” and then Trim method returns “abc xyz”.

Trim c что это

Конкатенация строк или объединение может производиться как с помощью операции + , так и с помощью метода Concat :

Метод Concat является статическим методом класса string, принимающим в качестве параметров две строки. Также имеются другие версии метода, принимающие другое количество параметров.

Для объединения строк также может использоваться метод Join :

Метод Join также является статическим. Использованная выше версия метода получает два параметра: строку-разделитель (в данном случае пробел) и массив строк, которые будут соединяться и разделяться разделителем.

Сравнение строк

Для сравнения строк применяется статический метод Compare :

Данная версия метода Compare принимает две строки и возвращает число. Если первая строка по алфавиту стоит выше второй, то возвращается число меньше нуля. В противном случае возвращается число больше нуля. И третий случай — если строки равны, то возвращается число 0.

В данном случае так как символ h по алфавиту стоит выше символа w, то и первая строка будет стоять выше.

Поиск в строке

С помощью метода IndexOf мы можем определить индекс первого вхождения отдельного символа или подстроки в строке:

Подобным образом действует метод LastIndexOf , только находит индекс последнего вхождения символа или подстроки в строку.

Еще одна группа методов позволяет узнать начинается или заканчивается ли строка на определенную подстроку. Для этого предназначены методы StartsWith и EndsWith . Например, в массиве строк хранится список файлов, и нам надо вывести все файлы с расширением exe:

Разделение строк

С помощью функции Split мы можем разделить строку на массив подстрок. В качестве параметра функция Split принимает массив символов или строк, которые и будут служить разделителями. Например, подсчитаем количество слов в сроке, разделив ее по пробельным символам:

Это не лучший способ разделения по пробелам, так как во входной строке у нас могло бы быть несколько подряд идущих пробелов и в итоговый массив также бы попадали пробелы, поэтому лучше использовать другую версию метода:

Второй параметр StringSplitOptions.RemoveEmptyEntries говорит, что надо удалить все пустые подстроки.

Обрезка строки

Для обрезки начальных или концевых символов используется функция Trim :

Функция Trim без параметров обрезает начальные и конечные пробелы и возвращает обрезанную строку. Чтобы явным образом указать, какие начальные и конечные символы следует обрезать, мы можем передать в функцию массив этих символов.

Эта функция имеет частичные аналоги: функция TrimStart обрезает начальные символы, а функция TrimEnd обрезает конечные символы.

Обрезать определенную часть строки позволяет функция Substring :

Функция Substring также возвращает обрезанную строку. В качестве параметра первая использованная версия применяет индекс, начиная с которого надо обрезать строку. Вторая версия применяет два параметра — индекс начала обрезки и длину вырезаемой части строки.

Вставка

Для вставки одной строки в другую применяется функция Insert :

Первым параметром в функции Insert является индекс, по которому надо вставлять подстроку, а второй параметр — собственно подстрока.

Удаление строк

Удалить часть строки помогает метод Remove :

Первая версия метода Remove принимает индекс в строке, начиная с которого надо удалить все символы. Вторая версия принимает еще один параметр — сколько символов надо удалить.

Замена

Чтобы заменить один символ или подстроку на другую, применяется метод Replace :

Во втором случае применения функции Replace строка из одного символа «о» заменяется на пустую строку, то есть фактически удаляется из текста. Подобным способом легко удалять какой-то определенный текст в строках.

Смена регистра

Для приведения строки к верхнему и нижнему регистру используются соответственно функции ToUpper() и ToLower() :

Trim characters from a C# string: Trim() , TrimStart() , and TrimEnd() explained

When our C# program works with strings of text, we every so often have to clean data first. One way to do so is by trimming specific characters from a string. Let’s see how to do that in C#.

IN THIS ARTICLE:

# Strip characters from the sides of a C# string

When we trim a string, we remove characters from its start and/or end. By cutting away specific characters from a string’s leading and/or trailing end we clean our strings. That helps our program to properly handle user input or data parsed from a webpage.

There are three string methods that strip characters from a string:

• Trim() removes characters from both sides of the string.
• TrimStart() strips characters from the start of the string.
• TrimEnd() cuts away characters from the end of the string.

Let’s take a closer look at how these work.

# Trim characters from both sides: C#’s Trim() method

With the Trim() string method we remove characters from the start and end of a string. There are two ways to use this method (Microsoft Docs, n.d. a):

• Trim() removes all whitespace characters from the start and end of the current string instance.

• Trim(char[]) strips all Unicode characters specified in the array. Those characters are removed from the string’s start and end.

# Features of C#’s Trim() method

The Trim() string method has the following characteristics (Microsoft Docs, n.d. a):

• Trim() returns a modified copy of the original string; it doesn’t change the source string.
• The method cuts away characters until it comes across a character not in its cut set. So Trim() continues until it reaches a non-whitespace character. And Trim(‘a’, ‘z’) stops when it comes across something else than a or b .
• When no characters can be trimmed, the source string is returned unchanged.
• When we use Trim() without an argument, it strips whitespace from both sides of the string.
• Trim() has been in C# for a long time. It first appeared in .NET Framework 1.1, .NET Core 1.0, and .NET Standard 1.0.

When you work with Trim() , keep in mind the following:

• The characters we specify are case sensitive: Trim(‘h’) does something else than Trim(‘H’) .
• The method removes characters in any order: Trim(‘x’, ‘y’) is the same as Trim(‘y’, ‘x’) . Use C#’s Replace() string method if you need to remove specific character patterns.
• Trim() works on both sides of the string independently. On each side it stops when it meets a character at that side of the string that isn’t in the cut set. So the method isn’t symmetric: it might remove 3 characters from the string’s start, but 475 from the string’s end.
• When we run Trim() on an empty string ( «» ), the method returns an empty string as well. But when called on a null string, the method raises a NullReferenceException exception.

# Example: trim characters from both sides of a C# string

Now let’s see how we use the Trim() method in a C# program. The console application below removes specific characters from a string:

In the Main() method we first make a string variable named example . Its content is a simple phrase with some non-letter characters. Let’s removes those from the string.

For that we call the Trim() method on the source string. Inside the parentheses of that method we specify the characters to remove: ‘>’ , ‘<‘ , and ‘ ‘ (space).

Trim() then cuts those characters from the string. But the method stops when it reaches a different character than those three. (That’s why, for example, the space character inside the string doesn’t get removed.)

We store the ‘cleaned’ string that Trim() returns in the exampleTrimmed variable. Then we call the Console.WriteLine() method to display both the original and trimmed string. Here’s how that console output looks:

# Strip characters from the start of a C# string: TrimStart()

With the TrimStart() method we remove characters from the start of the string. There are two ways to use this method (Microsoft Docs, n.d. b)

• TrimStart() removes all whitespace from the start of the current string instance.

• TrimStart(char[]) strips all Unicode characters specified in the array. Those characters are removed from the string’s start.

# Features of C#’s TrimStart() method

The TrimStart() method has the following characteristics (Microsoft Docs, n.d. b):

• TrimStart() returns a modified copy of the original string; it doesn’t change the source string.
• The method removes characters until it encounters a character not in its cut set. So TrimStart() continues until the first non-whitespace character. And TrimStart(‘y’, ‘z’) stops when meeting a character different than y or z .
• When there are no characters to remove, TrimStart() returns the source string unchanged.
• Without an argument, TrimStart() strips all whitespace from the string’s start.
• This string method has been with us for a long time. TrimStart() first appeared in .NET Framework 1.1, .NET Core 1.0, and .NET Standard 1.0.

These are some things to keep in mind when working with TrimStart() :

• The characters we specify are case sensitive: TrimStart(‘j’) does something else than TrimStart(‘J’) .
• The method strips characters in any order: TrimStart(‘a’, ‘b’, ‘c’) is the same as TrimStart(‘b’, ‘c’, ‘a’) . Use the Replace() method to strip character patterns from a string.
• When we call TrimStart() on an empty string ( «» ), the method returns an empty string as well. But when executed on a null string, we get a NullReferenceException error.

# Example: trim characters from the start of a C# string

Now let’s see how C#’s TrimStart() method in practice. The following console application strips characters from the start of a string:

Here, in the Main() method, we first make the example string variable. Its content is “Hello, World!” surrounded with non-letter characters. Let’s remove those from the start of the string.

For that we call the TrimStart() method on that string variable. Inside the method’s parentheses we specify four characters: ‘>’ , ‘ ‘ (space), ‘H’ , and ‘<‘ . Even though that last character isn’t in the string, we can still include it in the cut set and TrimStart() works fine.

TrimStart() then strips those characters from the start of the string, but stops when it meets a different character than those four. For our example string, that’s the letter e . We store the resulting trimmed string in the exampleTrimmed variable for use next.

Then we display both the original string and trimmed version with C#’s Console.WriteLine() method. Here’s how that looks:

# Cut characters from a string’s end: C#’s TrimEnd() method

With the TrimEnd() method we remove characters from the end of the string. There are two ways to use this method (Microsoft Docs, n.d. c):

• TrimEnd() removes all whitespace from the end of the current string instance.

• TrimEnd(char[]) cuts away all Unicode characters specified in the array. Those characters are removed from the string’s end.

# Features of C#’s TrimEnd() string method

The TrimEnd() method has these characteristics (Microsoft Docs, n.d. c):

• TrimEnd() returned a modified copy of the original string; it doesn’t change the source string.
• The method continues to cut away characters from the string’s end until it meets a character not in its cut set. So TrimEnd() goes on until the first non-whitespace character. And TrimEnd(‘o’, ‘p’) keeps going until a character different than o or p .
• When there are no characters to strip, TrimEnd() returns the source string unchanged.
• When we use the method without an argument, it removes all whitespace from the end of the string.
• TrimEnd() can be used by virtually every C# program. It first appeared in .NET Framework 1.1, .NET Core 1.0, and .NET Standard 1.0.

Some helpful things to know about the TrimEnd() method are:

• The characters we specify are case sensitive: TrimEnd(‘O’, ‘L’, ‘A’) does something else than TrimEnd(‘o’, ‘l’, ‘a’) .
• The method strips characters in any order. As such, TrimEnd(‘?’, ‘!’, ‘#’) is the same as TrimEnd(‘#’, ‘?’, ‘!’) . To replace specific patterns of characters, use C#’s Replace() string method.
• When we call TrimEnd() on an empty string ( «» ), the method returns an empty string as well. But when executed on a null string, the method triggers the NullReferenceException exception.

# Example: strip characters from a C# string’s tail end

Now let’s see how the TrimEnd() method works in practice. The following console application has that string method clean the right side of a string:

In this program we first make the example string variable. Its content is the “Hello, World!” phrase surrounded by > and < . Let’s clean the end of the string.

To make that happen we call the TrimEnd() method on the string instance. Between the method’s parentheses we specify three characters: ‘ ‘ (space), ‘!’ , and ‘<‘ . This has TrimEnd() cut away all occurrences of those three characters from the end of the string. If the method meets a different character than those three, it stops trimming and returns the modified string.

Next two Console.WriteLine() statements output the original and trimmed string. This is what output C# displays:

# Summary

C# has three string instance methods to trim specific characters from a string. Trim() removes characters from the start and end of a string. TrimStart() cuts away characters from the string’s start. And TrimEnd() removes from the string’s tail end.

We call each method on a string instance. And they all return a new, likely modified string. Their work doesn’t modify the original string.

Each method accepts a char array with the characters to trim. The method then removes every occurrence of those characters. But when it meets a character not in that cut set, it stops trimming.

References

Published December 6, 2019 .

# Related C# tutorials

An uppercase or lowercase string has every character in a certain case. C# can use a specific or independent culture for that. This tutorial explains how.

C# has no Left() , Right() , or Mid() string methods. But we can emulate them with Substring() . This article also shows useful extension methods for that.

Newlines are whitespace characters that signal the end of a line. This C# tutorial removes newline characters ( \n , \r , and \r\n ) from strings.

To clean a C# string we can delete whitespace. This article shows how to remove all whitespace, trim both sides, or just delete it at the start or end.

Welcome on Kodify.net! This website aims to help people like you reduce their programming curve. I hope you find the articles helpful with your programming tasks.

Want to know more about me? Check out the about page.

See all TradingView tutorials to learn about a lot of Pine Script features

C# String Trim Method (TrimStart, TrimEnd)

In c#, the string Trim method is useful to remove all leading and trailing whitespace characters from the specified string object.

Using the Trim() method, we can also remove all occurrences of specified characters from the start and end of the current string.

Following is the pictorial representation of using the string Trim() method to remove all the leading and trailing whitespaces from the defined string in the c# programming language.

If you observe the above diagram, we defined a string called “Welcome to Tutlane” and by using the string Trim() method we removed all leading and trailing white spaces from a defined string object.

C# String Trim Method Syntax

Following is the syntax of defining a string Trim method to remove all the leading and trailing whitespaces or specified characters from the string object in the c# programming language.

If you observe the above syntaxes, the first syntax is used to remove all whitespaces from the specified string’s start and end, and it won’t take any parameters.

The second syntax is used to remove leading and trailing occurrences of specified characters in an array from the current string object.

C# String Trim() Method Example

Following is the example of using the string Trim() method to remove the starting and ending of whitespaces or specified characters from the string object in the c# programming language.

namespace Tutlane
<
class Program
<
static void Main(string[] args)
<
// Trim Whitespaces
string str1 = » Welcome»;
string str2 = » to «;
string str3 = » Tutlane»;
Console.WriteLine(«Before Trim: <0> <1><2>«, str1, str2, str3);
Console.WriteLine(«After Trim: <0> <1><2>«, str1.Trim(), str2.Trim(), str3.Trim());
char[] trimChars = < '*', '@', ' ' >;
// Trim with Characters
string str4 = «@@** Suresh Dasari **@»;
Console.WriteLine(«Before Trim: <0>«, str4);
Console.WriteLine(«After Trim: <0>«, str4.Trim(trimChars));
Console.WriteLine(«\nPress Enter Key to Exit..»);
Console.ReadLine();
>
>
>

If you observe the above example, we used a string Trim() method with or without characters to remove all leading and trailing whitespaces and defined characters from the string object.

When you execute the above c# program, you will get the result as shown below.

If you observe the above result, the string Trim() method removes all trailing and leading whitespaces and sets of characters from the string object based on our requirements.

C# String TrimStart() Method

In c#, the string TrimStart() method is used to remove all leading occurrences of whitespaces or specified characters in an array from the string object.

Following is the example of using the TrimStart() method to remove all leading/starting occurrences of whitespaces or specified characters from the string object.

namespace Tutlane
<
class Program
<
static void Main(string[] args)
<
// Trim Whitespaces
string str1 = » Welcome»;
string str2 = » to «;
string str3 = » Tutlane»;
Console.WriteLine(«Before Trim: <0> <1><2>«, str1, str2, str3);
Console.WriteLine(«After Trim: <0> <1><2>«, str1.TrimStart(), str2.TrimStart(), str3.TrimStart());
char[] trimChars = < '*', '@', ' ' >;
// Trim with Characters
string str4 = «@@** Suresh Dasari **@»;
Console.WriteLine(«Before Trim: <0>«, str4);
Console.WriteLine(«After Trim: <0>«, str4.TrimStart(trimChars));
Console.WriteLine(«\nPress Enter Key to Exit..»);
Console.ReadLine();
>
>
>

If you observe the above example, we used a TrimStart() method to remove all leading occurrences of whitespaces and specified characters in a string object.

When you execute the above c# program, we will get the result as shown below.

If you observe the above result, the string TrimStart() method has removed only leading or starting whitespaces and defined characters from the given string object.

C# String TrimEnd() Method

In c#, the string TrimEnd() method is used to remove all trailing or ending occurrences of whitespaces or specified characters in an array from the string object.

Following is the example of using the TrimEnd() method to remove all trailing or ending occurrences of whitespaces or specified characters from the string object.

namespace Tutlane
<
class Program
<
static void Main(string[] args)
<
// Trim Whitespaces
string str1 = » Welcome «;
string str2 = » to «;
string str3 = » Tutlane «;
Console.WriteLine(«Before Trim: <0> <1><2>«, str1, str2, str3);
Console.WriteLine(«After Trim: <0> <1><2>«, str1.TrimEnd(), str2.TrimEnd(), str3.TrimEnd());
char[] trimChars = < '*', '@', ' ' >;
// Trim with Characters
string str4 = «@@** Suresh Dasari **@»;
Console.WriteLine(«Before Trim: <0>«, str4);
Console.WriteLine(«After Trim: <0>«, str4.TrimEnd(trimChars));
Console.WriteLine(«\nPress Enter Key to Exit..»);
Console.ReadLine();
>
>
>

If you observe the above example, we used a TrimEnd() method to remove all trailing occurrences of whitespaces and specified characters in a string object.

When you execute the above c# program, we will get the result as shown below.

If you observe the above result, the string TrimEnd() method has removed only trailing or ending whitespaces and defined characters from the given string object.

This is how we can use string Trim(), TrimStart(), TrimEnd() methods in c# to trim string objects in c# programming language based on our requirements.