Man With Code 👨‍💻

Covered in this episode:

• String Literals
• String Expressions
• String Methods
• Regular Expressions
• Getting User Input (gets)

Transcript: Hello Everyone and Welcome to Programming With Ruby Episode 6, Strings. I'm Tyler, your presenter. This is brought to you by manwithcode.com In this episode I will be telling you what string literals are. I will show you expressions you can use with strings, which are similar but still different than expressions with numbers. I will show you useful methods strings have. I will show you how to use regular expressions. Finally I will teach you how to get input from the user. On to the Code! String Literals According to wikipedia, string literals are the representation of a string value within the source code of a computer program. For example: [sourcecode language="ruby"] puts "Hello World" # Hello World is the string literal [/sourcecode] String Expressons The only string expressions are the plus and multiplication sign. The plus sign connects strings together, the multiplication sign repeats a string a certain number of times. Let me show you how it works: [sourcecode language="ruby"] "Hello " + "World!" #=> "Hello World!" "Hello " * 3 #=> "Hello Hello Hello" [/sourcecode] String Methods Here are some useful String methods: empty? tells you if you are dealing with an empty string length tells you how long a string is each_char lets you iterate over each character capitalize capitalizes the first character upcase makes all characters upper case downcase makes all characters lower case Regular Expressions Regular expressions are a way to match elements in other strings. It is easier to show you than to describe to you, so here we go! The simplest is substitution: [sourcecode language="ruby"] "Hello World".sub("Hello", "Goodbye") #=> "Goodbye World" [/sourcecode] But if you have more than one hello: [sourcecode language="ruby"] "Hello Hello Hello".sub("Hello", "Goodbye") #=> "Goodbye Hello Hello" [/sourcecode] This happens because the sub method only replaces the first occurrence of "Hello". The gsub method fixes this: [sourcecode language="ruby"] "Hello Hello Hello".gsub("Hello", "Goodbye") #=> "Goodbye Goodbye Goodbye" [/sourcecode] What if you want to manipulate parts of a string using regular expressions. The scan method is what you want! [sourcecode language="ruby"] # /n means new line "Who are you".scan(/../) { |x| puts x } #=> Wh\no \nar\ne \nyo # With no whitespace: "Who are you".scan(/\w\w/) { |x| puts x } #=> Wh/nar/nyo [/sourcecode] Regular Expressions are a vast topic that I can't completely cover here, so do a Google search to find out more. Getting User Input You can get user input with the "gets" method: [sourcecode language="ruby"] a = gets # The user inputs: I like pie puts a #=> "I like pie" [/sourcecode] That wraps it up for todays episode. Don't forget to donate, the link is to the right of this video If you have any questions or comments, leave a comment on this page or email me at [email protected] Bye!