Parsing of String class libraries

Example: string example = "Hello,world";

1. Property of String: Length: The user gets the lengths of the string: many times the function is to determine whether the length of the string is zero to determine whether a known object exists

Response.Write (example.  Length); Length is 11, note: subscript is 10, but the length is calculated starting from 1

2, the method of increasing the string:

A:insert (); Note: You must pass in two parameters, the first parameter is inserted from a position, the second parameter is inserted in the content

Response.Write (example. Insert (One, "How does You Do!")); The output is hello,world,how do do!

B:replace (); Note: You need to pass in two parameters, the first parameter is to find a character in the string that will be replaced, the first parameter is the character to be replaced

Response.Write (example. Replace ("World", "Provence")); The output is: hello,provence

C:string.  Join (); Note: You need to pass in two parameters, the first parameter is to split the connection with a string, the second argument is an array name

D: operator + number

3. How to delete a string:

A:remove (); Note: You can pass a parameter, you can also pass two parameters; A parameter represents the deletion of all subsequent characters from this subscript, and two parameters represent the deletion of a few characters from the subscript.

Response.Write (example.  Remove (5)); The result is: Hello

Response.Write (example. Remove (0,6)); The result: World

B:substring (); Note: You can pass a parameter, you can also pass two parameters, pass a parameter to intercept all the characters from this subscript, pass two parameters to intercept a few characters from this subscript

Response.Write (example. Substring (5)); The result is: the world

Response.Write (example. Substring (0,6)); The result is: Hello,

C:trim (); Note: You can pass in an array or do not pass in any parameters: remove spaces in a string

TrimEnd (); Remove whitespace from trailing string

TrimStart (); Remove whitespace from string header

4, the method of string modification:

A:toupper (); Convert all strings to uppercase

Response.Write (example.  ToUpper ()); The output is: Holle,world

ToLower (); Convert all strings to lowercase

Response.Write (example.  ToLower ()); The output is: "Hello,world

B:tochararray ();

5, the method of string query:

A:indexof (); Note: Pass a parameter if you find the subscript that returns the character, none returns-1

Response.Write (example.  IndexOf ("D")); return subscript as: 10

B:lastindexof (); Note: The index position of the last query begins to find

Response.Write (example. LastIndexOf ("H")); return subscript as: 0

C:lastindexofany (); Don't understand

D:endswith (); Query the end of a string there is no this character, there is a return true, none false

Response.Write (example.  EndsWith ("H")); Returns false

E:stractswith (); Query a string header there is no this character, there is a return true, none false

Response.Write (example.  Stractswith ("H")); Returns True

F:equals (); Determine if there is no this string, there is a return true, none false

Response.Write (example.  Equals ("H")); Returns false

Response.Write (example.  Equals ("Hello,world")); Returns True

G:string.  Equals (); Compares two strings for the same, returns true with different false

Response.Write (String.  Equals ("D", "D")); Returns True

Response.Write (String.  Equals ("D", "F")); Returns false

H:string.compare (); Compares the size between two strings to return 1, 0,-1

Response.Write (String.Compare (A, b)); A > B return 1

Response.Write (String.Compare (A, b)); A = b returns 0

Response.Write (String.Compare (A, b)); A < b return-1

6, splicing strings need to introduce using System.Text;

A:stringbuilder ();

StringBuilder sb= new StringBuilder ();

Sb. Append ("a");

Sb. Append ("B");

Sb. Append ("C");

Response.Write (sb.)  ToString ()); Output ABC

7. Format formatting (static method format)

Console.WriteLine (String. Format ("{0} + {1} = {2}", 1, 2, 1+2));
Console.WriteLine (String. Format ("{0}/{1} = {2:0.000}", 1, 3, 1.00/3.00));
Console.WriteLine (String. Format ("{0:yyyy mm month DD day}", DateTime.Now));

8, split as a string array (split)-reciprocal operation: union A string static method join (seperator,arr[])
         s = "Aa,bb,cc,dd";
         string[] arr1 = s.split (', '); //  splits the string with ', ' characters, returns an array of strings
         console.writeline (arr1[0]); //  output "AA"
        & nbsp Console.WriteLine (arr1[1]); //  output "BB"
         console.writeline (arr1[2]);  //  output "CC"
         console.writeline (arr1[3]); //  output "DD"
         console.writeline ();

s = "AA--BB--CC--DD";
string[] arr2 = S.replace ("--", "-"). Split ('-'); Tips for splitting with strings: first replace the string "--" with a single character "-" and then split the string with the '-' character to return an array of strings
Console.WriteLine (Arr2[0]); Output "AA"
Console.WriteLine (Arr2[1]); Output "BB"
Console.WriteLine (Arr2[2]); Output "CC"
Console.WriteLine (Arr2[3]); Output "DD"
Console.WriteLine ();

9. Concatenate into a string (static method Concat, static method join, and instance method Stringbuilder.append)
s = "A,b,c,d";
string[] Arr3 = S.split (', '); arr = {"A", "B", "C", "D"}

Console.WriteLine (String. Concat (ARR3)); Concatenate a string array into a string that outputs "ABCD"

Console.WriteLine (String. Join (",", ARR3)); Concatenate a string array into a string with "," as a split symbol, output "a,b,c,d"

StringBuilder SB =new StringBuilder (); Declares a string constructor instance
Sb. Append ("A"); Using string constructors to connect strings for higher performance
Sb. Append (' B ');
Console.WriteLine (sb.) ToString ());//Output "AB"

Parsing of String class libraries