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This article mainly shows you "what are the common extensions of string in C#", the content is simple and clear, and I hope it can help you solve your doubts. Here, let me lead you to study and learn "what are the common extensions of string in C#".

String is the most commonly used class in c #. Compared with its frequency of use, its operation is pitiful. There are only about 30 instance methods and more than ten static methods, which are far from meeting our daily needs.

This article uses the c # extension method to increase the function of string, to cite a few examples, can be regarded as throwing a brick to attract jade!

First, we extend the most commonly used static method IsNullOrEmpty of the string class to the "instance" method:

Public static bool IsNullOrEmpty (this string s) {return string.IsNullOrEmpty (s);}

Here is the calling code:

Public static void Test1 () {string s = ""; bool b1 = string.IsNullOrEmpty (s); bool b2 = s.IsNullOrEmpty ();}

Do not underestimate this step of improvement, the expansion can reduce the time we write code and improve the speed of our coding. If you doubt this, enter the code on lines 4 and 5 by hand 100 times (you can't copy and paste) and you'll see!

If you want, you can also expand to "IsNotNullOrEmpty".

Let's take a look at the FormatWith extension.

Public static string FormatWith (this string format, params object [] args) {return string.Format (format, args);} public static void Test2 () {string today = "today is: {0: yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

It's also very simple. Let's talk a little bit about efficiency here. The string.Format function has several overloads:

Public static string Format (string format, params object [] args); public static string Format (string format, object arg0); public static string Format (string format, object arg0, object arg1); public static string Format (string format, object arg0, object arg1, object arg2); public static string Format (IFormatProvider provider, string format, params object [] args)

Although the Format in line 1 is powerful enough to replace the middle three, it is not efficient. The middle three overloads are for performance reasons.

If you value efficiency performance, it is not possible to use only one FormatWith extension, you can refer to the overload of Format and extend a few more!

Regular expressions are still used to deal with the string * * in .net. Let's extend some of its functions to string:

Public static bool IsMatch (this string s, string pattern) {if (s = = null) return false; else return Regex.IsMatch (s, pattern);} public static string Match (this string s, string pattern) {if (s = = null) return ""; return Regex.Match (s, pattern) .value;} public static void Test3 () {bool b = "12345" .IsMatch (@ "\ d +") String s = "ldp615" .match ("[a-zA-Z] +");}

Using Regex, you want to reference the namespace "System.Text.RegularExpressions".

After the extension, we can directly use the c # extension method without having to refer to the namespace or write "Regex".

Regex's Replace method is also more commonly used and can also be extended to string.

Here are the actions related to int:

Public static bool IsInt (this string s) {int i; return int.TryParse (s, out I);} public static int ToInt (this string s) {return int.Parse (s);} public static void Test4 () {string s = "615"; int I = 0; if (s.IsInt ()) I = s.ToInt ();}

The conversion to DateTime can be done in the same way.

If you have used CodeSmith, you should be familiar with the following applications:

Public static string ToCamel (this string s) {if (s.IsNullOrEmpty ()) return s; return s [0] .ToString (). ToLower () + s.Substring (1);} public static string ToPascal (this string s) {if (s.IsNullOrEmpty ()) return s; return s [0] .ToString (). ToUpper () + s.Substring (1);}

There is no need to explain, everyone can understand it.

It can also be extended like Left and Right for string processing in sql, which is relatively simple and easy to implement.

It can also realize the singularity conversion of English nouns, which is not a big application scenario and relatively troublesome to achieve.

The extension of string in the C # extension method is much more than that. According to your actual needs, you can expand it as long as it is easy to use.

The above is all the content of the article "what are the common extensions of string in C#". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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