C# String Examples

String initialization 🔗

string s1 = "hello";
string s2 = null;
 
string s3 = new String('a', 6);
// result will be the string "aaaaaa"
string s4 =
new String(
new char[]{'w', 'o', 'r', 'l', 'd'});
var s5 = String.Empty;
if (s5.IsNullOrWhiteSpace()){
Console.WriteLine([Empty String]);
}

Main methods of the String class:

• Compare,CompareOrdinal: compares two strings
• Contains: whether the substring is contained in the string
• Concat: concatenate strings
• CopyTo: copies to another line
• EndsWith: whether end of string matches substring
• Format: formats a string
• IndexOf: index of first occurrence
• Insert: inserts a substring into a string
• Join: joins array elements
• LastIndexOf: index of last occurrence
• Replace: replaces
• Split: splits into an array
• Substring: extracts a substring from a string
• ToLower: to lowercase
• ToUpper: upper case
• Trim: remove spaces

long number1 = 19876543210;
Console.WriteLine(
number1.ToString("+# (###) ###-##-##"));
// +1 (987) 654-32-10
Console.WriteLine(
$"{number1:+# ### ### ## ##}");
// +1 987 654 32 10
double number = 23.7;
stringresult =
   String.Format("{0:C}", number);

All used formats: 🔗

• C / c currency format
• D / d Integer format
• E / e Exponential notation
• F / f Fixed-point decimal format
• G / g Specifies the shorter of the two formats: F or E
• N/n fixed-point decimal format
• p / p Specifies whether a percent sign is displayed next to a number
• X / x Hexadecimal number format

• ' Single quote -" double quote
• \ backslash
• \0 Null
• \a Warning -\b backspace
• \f Form feed
• \n Newline
• \r carriage return
• \t Horizontal tab
• \v Vertical tab
• \u (UTF-16) (0000 - FFFF; \u00E7 = “ç”)
• \U (UTF-32) ( 000000 - 10FFFF; \U0001F47D = “👽”)
• \x \xH[H][H][H] ( 0 - FFFF; \x00E7 or \x0E7 or \xE7 = “ç”)