.NET API Docs

System.String

The String class represents immutable text as a sequence of Unicode characters.

Namespace

System

Assembly

System.Runtime.dll

Inheritance

Object → String

Constructors

public String(char[] value);
public String(char c, int count);
public String(char[] value, int startIndex, int length);
public String(ReadOnlySpan<char> value);
public String(string? value);

Properties

NameTypeDescription
LengthintGets the number of characters in the current string.
Chars[int index]charGets the character at the specified position.

Methods

Manipulation
  • static string Concat(params string?[]? values)
  • string Substring(int startIndex)
  • string Substring(int startIndex, int length)
  • string Replace(string oldValue, string? newValue)
  • string ToUpper()
  • string ToLower()
  • string Trim()
  • string[] Split(params char[] separator)
Comparison
  • int CompareTo(string? strB)
  • bool Equals(string? value)
  • static bool Equals(string? a, string? b)
  • static bool IsNullOrEmpty(string? value)
  • static bool IsNullOrWhiteSpace(string? value)

Examples

// Concatenating strings
string first = "Hello";
string second = "World";
string combined = string.Concat(first, " ", second); // "Hello World"

// Using interpolation
int year = 2025;
string message = $"The year is {year}."; // "The year is 2025."

// Splitting and joining
string csv = "apple,banana,cherry";
string[] fruits = csv.Split(',');
string rejoined = string.Join(" | ", fruits); // "apple | banana | cherry"

See Also