Use of strings 2

What is the difference between declaration of string and its initialization ?

How to add one string another string?

// Declare without initializing.
string message1;
 
// Initialize to null.
string message2 = null;

LO: Use of procedures and functions for processing the strings

Evaluation Criteria:

Knowledge
• Know how to display Date in a string
• Know how to display Length of string

Understanding
• Describes how to search a word in sentence
• Describes how to work with Substring method of string

Application
• Write code for processing the strings using functions
• Write code for processing the strings using procedures

Start index

Frequency

substring

split

pattern

contiguous

Useful expressions for dialogs :

Well, we should use the loop to find the frequency of a given word in … .
For example, substring is used to get first n characters substring from a string … .
Obviously, the Substring method makes it a lot easier to process strings in comparison with … .

Task 1 . Search a word (Handout 1)

In C#, a string is represented by the String class. The String.Substring method retrieves a substring from a string instance in C#. The method has the following two overloaded forms. 

Substring(Int32) - Retrieves a substring from the specified position to the end of the string.
Substring(Int32, Int32) - Retrieves a substring from this instance from the specified position for the specified length.

String characters are zero-indexed. Means, the position of the first characters in a string starts at 0th position. 

Let’s say, you want to get a substring of first 12 characters from a string.

We can use the Substring method and pass it starting index 0 and length of the substring 12 to get first 12 char substring from a string.

// A long string    

string bio = "Mahesh Chand is a founder of C# Corner. Mahesh is also an author, speaker, and software architect. Mahesh founded C# Corner in 2000.";    
    
// Get first 12 characters substring from a string  
  
string authorName = bio.Substring(0, 12);    
Console.WriteLine(authorName);

Task 2. (handout 2)

Substring method use case

Summary

Questions:

What is the substring?

When to use Substring method?