Related methods of string in C#

The following methods generally have many overloaded forms. As a beginner, let me record the ones I have used. . . Others can be added little by little in the future;

Go straight to the example. First define two strings str1, str2 (don't complain about naming ==)

string str1,str2;

Get the length of the string

int string.Length{get;};

1 str1="012345abc";
2 Console.WriteLine(str1.Length);

//output:9

convert case

1  string  string .ToUpper(); // turn to uppercase 
2  string  string .ToLower(); // turn to lowercase

str1 = " 123abcABC one two three " ; 
Console.WriteLine(str1.ToUpper()); 
Console.WriteLine(str1.ToLower()); 

// output: 
    123ABCABC one two three 
    123abcabc one two three

compare strings

bool string.Equals(string);
bool Equals(object,object);

1 str1 = " 123ABC " ;
 2 ste2 = " 123abc " ;
 3  
4 Console.WriteLine(str1.Equals(str2)); // return false 
5 Console.WriteLine(Equals(str1,str2)); // return false 
6 Console.WriteLine(str1.Equals(str2,StringComparison.Ordin alIgnoreCase)); // Return true
 7  // Among them, StringComparison.OrdinalIgnoreCase enumeration, ignoring case comparison

 split string

1 string[] string.Split(params char[]);

 

str1 = " 123abc " ;
 string [] newSte = str1.Split(' a' );
 foreach ( var item in newStr ) 
{ 
    Console.WriteLine(item); 
} 
/* The output is: 
123 
bc 
*/
    

 

Because the parameter type is modified by params, the Split() method can directly pass in multiple characters instead of just character arrays, such as

str.Split('a','2');

 

Then he will be divided into three segments based on a and 2.

Check if substring exists

bool string.Contains(string);

not much to say

Determine the beginning and end, obtain the string position and intercept the string

These four 666, combined with outstanding effect

bool  string .StartWith( string ); // Judge whether the beginning is the input parameter 
bool  string .EndWith( string ); // Judge whether the end is the input parameter 
int  string .IndexOf( string ); // Get the position where the substring first appears 
string  string .SubString( int length); // Intercept the substring
 string  string .SubString( int start, int lenhth) ;

1  string str = " <sc>ascdsc " ;
 2  if (str.StartsWith( " < " )) // if the beginning is < 
3  {
 4      if (!str.EndsWith( " > " )) // if the end is not > 
5      {
 6           int n = str.IndexOf( " > " );
 7          string ans = str.Substring(n + 1 );
 8          Console.
WriteLine(ans);
 9     }
10 }
11 //The output is: ascdsc

 

 

Reprinted in: https://www.cnblogs.com/Yukisora/p/7017208.html