This document provides an overview of strings in C# programming. It defines what a string is, how to declare string variables and literals, and describes several common string methods like ToUpper(), Trim(), Contains(), Split(), IndexOf(), and Replace(). The objectives are to learn how to construct programs that format strings and to explain how string methods are implemented in C# to manipulate text content. Examples of string method usage are provided.

1. C# Strings
MODULE 6

2. COURSE INTENDED
LEARNING OUTCOMES
CILO 6:
Construct programs that formats strings.

3. Wacky Words

4. Lesson Objectives
Apply the different methods in a C# program.
Explain how they are implemented in C# and process text content.
Learn the different methods for manipulating a text.

5. “
“Delivering good software
today is often better than
perfect software tomorrow,
so finish things and ship.”
― David Thomas,

6. String Defined
• A string is a sequence of characters stored in a certain address in
memory.
• In layman’s term, a string is a sequence of characters enclosed in
double quotation marks.
• The class System.String enables us to handle strings in C#.
• For declaring the strings we will continue using the keyword string,
which is an alias in C# of the System.String class from .NET
Framework.
• The work with string facilitates us in manipulating the text content:
construction of texts, text search and many other operations.

7. Declaring a String Variable
• A string variable is a sequence of characters whose value changes
throughout the program.
• The value of the string depends on the user input.

8. Syntax:
string variable_name;
string myschool;

9. Declaring a String Literal
• A string literal, also called a string constant is a sequence of characters
whose value does not changed.
• The value of the string is fixed throughout the program.

10. Syntax:
string variable_name = “value”;
string my school = “Adamson U”;

11. Clone()
Returns a reference to this
instance of String.

12. ToUpper()
ToUpper function converts
string to upper case.

13. ToLower()
ToLower function converts
string to upper case.

14. Trim()
Trim function removes extra
spaces from the beginning and
the ending of string.

15. Contains()
Contains method return bool
value, it checks whether
specified string or character
exist in string or not.

16. ToCharArray()
Convert a string to array of
character.

17. Substring()
Substring method returns
substring of a string.

18. StartsWith()
StartsWith method checks
whether the first character of
a string is same as specified
character .It returns bool
value.

19. Split()
Split function splits the
string on the supplied
value.It return the array of
string.

20. Split()
Split function splits the
string on the supplied
value.It return the array of
string.

21. EndsWith()
Determines whether the end of
this string instance matches a
specified string.

22. IndexOf()
Reports the zero-based index
of the first occurrence of a
specified Unicode character or
string within this instance.
The method returns -1 if the
character or string is not
found in this instance.

23. LastIndexOf()
Reports the zero-based index
position of the last
occurrence of a specified
Unicode character or string
within this instance. The
method returns -1 if the
character or string is not
found in this instance.

24. Replace()
Returns a new string in which
all occurrences of a specified
Unicode character or String in
the current string are
replaced with another
specified Unicode character or
String.

25. Replace()
Returns a new string in which
all occurrences of a specified
Unicode character or String in
the current string are
replaced with another
specified Unicode character or
String.

26. Sample Program:

27. Thanks!
Any questions?

28. References:
• https://www.tutorialsteacher.com/csharp
• https://www.tutlane.com/tutorial/csharp
• https://www.programiz.com/csharp-programming
• https://www.geeksforgeeks.org