Study notes - C string delete character

Method 1：s = s.Substring(0,s.Length - 1); Delete the last character of the string  ;

s = s.Substring(0,s.Length - 1)

extend ：

 （1）String.Substring (Int32 index) ： Reserve string subscripts index After the string ;

eg：s.Substring(3);

For from s Subscript position is 3 Start of character , Character substring after interception ,3 Indicates the start bit of the intercepted substring ;

s by ：“asCded”;x by ：“ded”;

（2）String.Substring (Int32 index1, Int32 index2) ： Keep subscript from string index1 From character of , The length is index2 The string of ;

eg：string x=s.ubstring(3,2）;

x For from s Subscript position is 3 Start of character , The intercepted length is 2 Character substring of ;

3 Indicates the starting position of the intercepted substring ,2 Indicates the length of the intercepted substring ;

s by ：“asCded”;x by ：“de”;

Method 2：s=s.Trim(); Delete the space at the beginning and end , Encounter the end of the first non space character ;

s=s.Trim();

extend ：

（1）String.Trim(char myChar): Remove the matching characters from the front and back of the string respectively myChar The character of a character , Until the first mismatch of traversal myChar The characters in the character set , Stop traversing the removal operation ;

Trim If you don't fill in the following parentheses , By default, space characters are removed .

eg:
y = s.Trim();
s by ：“ 075 pop ”;x by ：“075 pop”;

y = s.Trim('_');
s by ：“_075 pop_”;x by ：“075 pop”;

eg:
y = s.Trim();
s by ：“ 075 pop ”;x by ：“075 pop”;

y = s.Trim('_');
s by ：“_075 pop_”;x by ：“075 pop”;

（2）String.Trim(char[ ]  myChar)： Remove the matching characters from the front and back of the string respectively myChar Characters in the character set , Until the first mismatch of traversal myChar The characters in the character set , Stop traversing the removal operation ;

eg：

char[] myChar= {'1','2','3','5','6','7','8','9','0'};// No, ‘4’;

x =s.Trim(myChar);

s by ：“238ase 075 pop uuu2416”;x by ：“ase 075 pop uuu24”;

eg：

char[] myChar= {'1','2','3','5','6','7','8','9','0'};// No, ‘4’;

x =s.Trim(myChar);

s by ：“238ase 075 pop uuu2416”;x by ：“ase 075 pop uuu24”;

char Character interpretation ：

myChar Is included 0-9, But does not include 4 Set of characters ;

s.Trim(myChar); explain ：

Is from the string s Inside out to inside （ Two ends to the middle ） Iterate through the string in turn , The traversal characters match mychar The character set is deleted , Until I meet the first one who doesn't belong to myChar The characters in the character set , Stop traversing the delete operation .

Process explanation ：

1） Start from the front ,‘2’,‘3’,‘8’, All in myChar Character set , They all match , Delete these three characters ;

2） When you traverse to ‘a’ This character , and myChar There is no match in the character set , Stop operation here . The following characters are no longer traversed ;

3） meanwhile , Also start from the end of the string ,‘6’,‘1’, Energy and harmony myChar The characters in the character set match , Delete these two characters .

4） When you traverse to ‘4’ When this character , and myChar There is no match in the character set , Stop operation from here , The previous characters are no longer traversed and checked .

5） So the final result is ：“ase 075 pop uuu24”;

（3）String.TrimStart(char[ ]  myChar)：  Remove the characters at the beginning of the string

Same as Tirm(), Empty in parentheses , The default space character ;

eg1:
y = s.TrimStart();
s by ：“ 075 pop ”;x by ：“075 pop ”;

eg2：

char[] myChar= {'1','2','3','5','6','7','8','9','0'};// No, ‘4’;

x =s.TrimStart(myChar);

s by ：“238ase 075 pop uuu2416”;x by ：“ase 075 pop uuu2416”;

For detailed explanation, please refer to the above Trim();

（4）String.TrimEnd(char[ ] myChar)： Remove the characters at the end of the string

Same as Tirm(), Empty in parentheses , The default space character ;

eg1:
y = s.TrimEnd();
s by ：“ 075 pop ”;x by ：“ 075 pop”;

eg2：

char[] myChar= {'1','2','3','5','6','7','8','9','0'};// No, ‘4’;

x =s.TrimEnd(myChar);

s by ：“238ase 075 pop uuu2416”;x by ：“238ase 075 pop uuu24”;

For detailed explanation, please refer to the above Trim() and TrimStart();

eg1:
y = s.TrimEnd();
s by ：“ 075 pop ”;x by ：“ 075 pop”;

eg2：

char[] myChar= {'1','2','3','5','6','7','8','9','0'};// No, ‘4’;

x =s.TrimEnd(myChar);

s by ：“238ase 075 pop uuu2416”;x by ：“238ase 075 pop uuu24”;

Method 3：s = s.Remove(s.Length-1,1); Start with the last bit of the string , Remove a character .（ That is, remove the last character ）

eg： p = s.Remove(s.Length - 1,1);

s by "awxno";p by “awxn”

string s = "ab_eeK_";
p = s.Remove(s.Length - 1,1);

//p by ："ab_eeK"; Last “_” It's been removed ;

extend ：

（1）string.Remove(Int32 beginIndex);

Delete the string from beginIndex All characters after subscript start ;（ Only keep in the string beginIndex Previous characters ）;

Eg：

p = a.Remove（3）;

a by ：“123abscOpq”;p by ：“123”;

p = a.Remove（3）;

a by ：“123abscOpq”;p by ：“123”;

（2）string.Remove(Int32 beginIndex, Int32 length);

Delete string beginIndex After subscript length Characters of length ; 

Eg：

p = a.Remove（3,2）;

a by ：“123abscOpq”;p by ：“123scOpq”;

p = a.Remove（3,2）;

a by ：“123abscOpq”;p by ：“123scOpq”;