String and string, Stringstring

String and string, Stringstring

StringAndStringDifference

From the perspective of location:

 1.String is the String in. NET Framework, and the string in lower case is the string in C # language.

2. If you delete using System;, there is no upper-case String. System is a function name in the. NET Framework class library.

In terms of nature:

1.String is a keyword and String is a class. string cannot be the name of a class, structure, enumeration, field, variable, method, or attribute.

2.When writing code in C #, try to use a lower-case string, which is more compliant. If efficiency is pursued, you can use a String in upper case, because after compilation, lowercase strings are converted to uppercase strings, which can reduce the compilation load and improve the running efficiency.

3.String represents a string of Unicode characters. String is the alias of a string in. NET Framework. It is more intuitive to test the equality of strings.

StringDetails:

String s = string. Empty: A string variable pointing to an Empty string. The. s variable can be used, for example, s. Length.

String s = ""; an empty string pointing to "\ 0" occupies a byte storage space, because the Escape Character \ 0 indicates that the string ends. s variable can be used, such as s. Length

String s = null; a variable that does not belong to any bucket. s cannot be used.

Single Character Segmentation:

String s = "abcdeabcdeabcde ";

String [] sArray = s. Split ('C ');

Foreach (string I in sArray)

Console. WriteLine (I. ToString ());

Output the following results:

AB

Deab

Deab

De

Separate multiple characters:

String s = "abcdeabcdeabcde

String [] sArray1 = s. Split (new char [3] {'C', 'D', 'E '});

Foreach (string I in sArray1)

Console. WriteLine (I. ToString ());

You can output the following results:

AB

AB

AB

Separate multiple characters(Regular Expression):

String content = "agcsmallmacsmallgggsmallytx ";

String [] resultString = Regex. Split (content, "small", RegexOptions. IgnoreCase)

Foreach (string I in resultString)

Console. WriteLine (I. ToString ());

Output the following result: agc

Mac

Ggg

Ytx