Various String Class Methods in C#

Introduction to String Methods in C#

The string class in C# provides a wide range of methods for manipulating, comparing, and querying strings. These methods make it easier to perform common operations such as concatenation, searching, splitting, and formatting strings.

Concat() Method

The Concat() method is used to concatenate multiple strings into a single string.

Example: Using Concat() Method

string firstName = "John";
string lastName = "Doe";
string fullName = string.Concat(firstName, " ", lastName);

Console.WriteLine(fullName);  // Output: John Doe
        

In this example, the Concat() method concatenates the first name and last name with a space in between.

Equals() Method

The Equals() method is used to compare two strings for equality. It returns true if the strings are equal, and false otherwise.

Example: Using Equals() Method

string str1 = "Hello";
string str2 = "hello";
bool result = str1.Equals(str2, StringComparison.OrdinalIgnoreCase);

Console.WriteLine(result);  // Output: True
        

In this example, Equals() is used with StringComparison.OrdinalIgnoreCase to compare the strings in a case-insensitive manner.

Substring() Method

The Substring() method is used to extract a portion of a string starting at a specified index.

Example: Using Substring() Method

string str = "Hello, World!";
string subStr = str.Substring(7, 5);

Console.WriteLine(subStr);  // Output: World
        

In this example, Substring() extracts a substring starting at index 7 and spanning 5 characters.

Replace() Method

The Replace() method is used to replace all occurrences of a specified string or character in a string with another specified string or character.

Example: Using Replace() Method

string str = "I love C#";
string newStr = str.Replace("C#", "programming");

Console.WriteLine(newStr);  // Output: I love programming
        

In this example, the Replace() method replaces "C#" with "programming" in the original string.

Split() Method

The Split() method is used to split a string into an array of substrings based on a specified delimiter.

Example: Using Split() Method

string str = "apple,banana,orange";
string[] fruits = str.Split(',');

foreach (string fruit in fruits)
{
    Console.WriteLine(fruit);
}
// Output:
// apple
// banana
// orange
        

In this example, the Split() method splits the string at each comma, producing an array of fruit names.

Key Points to Remember

• The Concat() method concatenates multiple strings into one.
• The Equals() method compares two strings for equality and supports case-insensitive comparisons.
• The Substring() method extracts a portion of a string starting at a specified index.
• The Replace() method replaces all occurrences of a substring or character in a string with another substring or character.
• The Split() method divides a string into an array of substrings based on a specified delimiter.