This week I learned...

Week: 03/05/2023 - 03/11/2023

Working with Strings in Ruby

Input:

'Single quoted strings #{represent} "characters" verbatim.'

Output:

Single quoted strings #{represent} "characters" verbatim.

Input:

"Double-quoted strings make some substitutions: #{2 + 4}"

Output:

Double-quoted strings make some substitutions: 6

To join Strings, you can interpolate or concatenate

• String concatenation

  • joining of strings
  • can join strings together using "" and + between strings
  • you have to add " ", an empty string with a space to prevent two words being put together
  • myvar can be a variable inserted with a string and can add other strings with the plus sign +
  • if you do += the myvar will be have the new concatenation as the new string
  • strings can only be concantenated with other strings

• String interpolation

  • interpolation #{} can be used within double quoted strings and it will substitute the result of a ruby code into the middle of the string
  • the interpolation will be evaluated and the result will be converted into a string

Interactive Ruby (irb)

• can use IRB (interactive ruby) which is integrated in Ruby if you type "irb" and hit return in terminal
• irb will show you the result of each expression, you dont need to call "puts" or anything
• type "exit" and then enter to exit out of IRB

p vs puts vs print method

• Ruby provides a method p which is different than print and puts
• p method allows us to inspect the values we pass to it and to print them out approximate the same way they would appear in a ruby code

Input: puts

            puts "   "
            puts ""
            puts nil
            puts []

The output is an empty terminal

Input: print

            print "    "
            print ""
            print nil
            print []

The output is []%

Input: p

            p "    "
            p ""
            p nil
            p []

The output is:

            "     "
            ""
            nil
            []

Some escape sequences
- \n skips to a new line
- \t indents a text
- \" inserts "double quotes"
- \' inserts 'single quotes'
- \ inserts a backslash: \

Input: example

        puts "first line
        second line"

        puts "     new paragraph"
        puts "  He said, "Whoa.""

to fix the line above use escape sequences

    puts "first line\nsecond line"
    puts "\tnew paragraph"`
    puts "He said, \"whoah\""

Next Week: Ruby Objects