5.0: Strings

STRINGS

In this module we'll study String types in more depth, and study three ways to manipulate strings.

Description

Strings, as briefly mentioned in a previous module, are just a collection of characters that can be stored and used throughout an application in different ways. Almost any text, single character, or number can be a string in C#. Strings are initialized by using double quotes in C#.

File Location

1. Right click on the solution. Click Add > New Project.

2. Select Console App (.NET Framework).

3. Name it 05_strings.

4. Write your code for this module within the Program.cs of that project.

Declaring and Initializing Strings

See if you can remember how to do the following things:

1. declare a string called myName, but don't give it a value yet.

2. Declare a string and initialize it by giving it a value.

Answers

1. string myName;

2. string wholeName = "Douglas Crockford"

Joining Strings

In this module we'll explore common ways to manipulate strings.

Three Types of string manipulation

There are three common ways of manipulating strings in C#:

• Concatentation

• Composite Formatting

• Interpolation

Concatenation

Let's start with string concatenation. In the Program.cs file in 05_strings, add the following code:

string first = "The cars we sell are ";
string second = "BMW, Lexus, and Mercedes.";
Console.WriteLine(first + second);

//result: The cars we sell are BMW, Lexus, and Mercedes.

With concatenation we use the + operator to combine two strings. Notice the space after are and before the closing ". If there was no space, you would need to add one, like this:

Console.WriteLine(first + " " + second);

Composite Formatting:

Composite formatting is another common way of manipulating strings. Add the following code to your Program.cs file:

string firstName = "Jenn";
string lastName = "Williams";
                                //1         //2
Console.WriteLine("Her name is {0} {1}.", firstName, lastName);

//result: Her name is Jenn Williams.

Take a note of a few details here: 1. Composite formatting uses curly braces inside the string and a number inside the curly brace. Notice that the first variable is a 0 value in the curly brace, like an array.

1. A comma follows the string, then each variable name is added.

String Interpolation:

String interpolation is another common method of manipulating strings. Code and study the following:

string firstName = "Robin";
string lastName = "Holler";
                //1                 //2
Console.WriteLine($"Her name is {firstName} {lastName}");

Note a few things: 1. String interpolation requires that we use the $ before the string. 2. The dollar sign allows us to pass variables in directly to the curly braces.

Challenge

• Practice these 3 ways of joining strings together in your Program.cs file.