C # (String method Summary)

1. Conversion of character arrays to strings

(1) ToCharArray () Converts a string into a character array

String s= ' I like blogs ';

Char[] Chs=s.tochararray ();

(2) The character array new string () gets the string

S=new string (CHS);

2. Determine if the string is empty: IsNullOrEmpty (), the return value is type bool

String S=null:

if (String.IsNullOrEmpty (s))

{

Console.WriteLine ("String is empty");

}

Else

{

Console.WriteLine ("String is not empty");

}

3. String comparison is equal: equal (), which compares the address (this sentence is not quite understood in some places), stringcomparison.ordinalignorecase means ignoring case

String s1= "ABCD";

String s2= "ABCD";

if (S1. Equal (S2,stringcomparison.ordinalignorecase))

{

Console.WriteLine ("Same");

}

Else

{

Console.WriteLine ("Different");

}

4. Find the position of a character in a string

(1) IndexOf (): Find the first place a character appears in a string

String s= "I like blogs";

int index=s.indexof (' Hi ');//The result is index=1

(2) LastIndexOf ()

String s= "I like blogs, like here";

int index=s.lastindexof (' Hi ');//The result is index=6

(3) Two methods can be followed by a character parameter after a shape parameter, indicating the beginning of the first search

String s= "I like blogs";

int index=s.indexof (' Hi ', 1);//start with the first one, including the first

5. String intercept function substring ()

String s= "ABCDEFG";

S=s.substring (1,4);//means intercept from the first, intercept to fourth but not fourth; the second argument does not, which means intercept to the very end

6.split ()

string s = "A,--B";

string[] NewS = S.split (new char[] {", '-', ', '}, stringsplitoptions.removeemptyentries);//new char[] {to remove                                                                                                                                              The characters in the S string},stringsplitoptions.removeemptyentries the parameters of the The function is to remove the space in the resulting new string array

News[0]= "a";

News[1]= "B";

7. String insertion function join ()

String[] names = {"Zhang San", "John Doe", "Harry", "Zhao Liu"};

string S1 = string. Join ("|", names);//s1= "Zhang San | john Doe | harry | Zhao LIU |"

String s2 = string. Join ("|", 1,3.14,true, ' C ', 5000m, "Zhang San");//s2= "1|3.14|true|c|5000| Zhang San |"

8. String formatting function format ()

String s=string. Format ("I am {0} years old}",//s= "I am 20 years old this year")

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C # (String method Summary)