String Methods

Syntax

string.MethodName(arguments)

Examples

string csv = "Fola,Zain,Jamal";
string[] names = csv.Split(',');

foreach (string name in names)
{
    Console.WriteLine(name);
}

string joined = string.Join(" & ", names);
Console.WriteLine(joined);  // Fola & Zain & Jamal

string sentence = "The quick brown fox";

Console.WriteLine(sentence.Contains("quick"));       // true
Console.WriteLine(sentence.IndexOf("brown"));         // 10
Console.WriteLine(sentence.Replace("fox", "dog"));    // The quick brown dog
Console.WriteLine(sentence.StartsWith("The"));        // true

string empty = "";
string whitespace = "   ";
string value = "hello";

Console.WriteLine(string.IsNullOrEmpty(empty));           // true
Console.WriteLine(string.IsNullOrWhiteSpace(whitespace));  // true
Console.WriteLine(string.IsNullOrEmpty(value));            // false

string label = "Score";
Console.WriteLine(label.PadRight(10) + "|" + "95".PadLeft(5));

int number = 7;
Console.WriteLine(number.ToString("D3"));  // 007

Best practices

• Use string.IsNullOrEmpty() or string.IsNullOrWhiteSpace() instead of manually checking for null and empty separately
• Use string.Join() instead of a manual loop with string concatenation when combining array elements into one string
• Chain string methods when it improves readability (input.Trim().ToLower()), but break into steps once a chain gets too long to read at a glance
• Use StringComparison.OrdinalIgnoreCase explicitly for case-insensitive comparisons rather than lowercasing both sides first

At a glance

Purpose

Applications on the .NET platform

File extension

.cs

Runs in

.NET runtime

Usually used with

.NET SDK and libraries

Specifications & further reading

• C# language reference

Related C# documentation