# START COPY AND PASTE HERE
# Ruby Hash Sorting Tutorial
# initialize hash using following syntax: hashName = { }
# initialize hash items using hash-rocket => syntax
# example: food1 => chlorella
# food1 is a key, chlorella is a value
# a hash can have multiple values for one key
superfoods = {
"food1" => "chlorella", # Add items with => syntax
"food2" => "nori",
"food3" => "bee pollen",
"food4" => "sauerkraut",
"food5" => "kimchi"
}
puts # code readability
puts "SUPERFOODS HASH food3 IS:" # print title
puts superfoods["food3"]; # print food3
puts "ALL SUPERFOODS KEYS" # print title
puts superfoods.keys # print all hash keys
puts "ALL SUPERFOODS VALUES"
puts superfoods.values # print all hash values
puts # prints empty line for code readability
puts
# SYNTAX DETAILS
# =======================
# Hash sorting syntax: hashName.sort{| range | sortOrder }.each {| element | puts }
# range = rows of keys and values in data set
# range has arbitrary letters for data, a for keys, b for values, so | a, b |
# sortOrder = process which items (columns) in the list?
# sortOrder. In this case a[0] is the first item in Keys, the first data set
# .each is a Ruby method to COUNT - LOOP through data items until done
puts
puts "SORTING CODE STARTS HERE"
puts "======================="
puts
puts "KEYS COLUMN FIRST in ALPHA ORDER"
# Hash sorting syntax: hashName.sort{| range | sortOrder }.each {| element | puts }
# a = keys column, b = values column
# a <=> b is alpha or reverse-alpha
# a[0] or a[1] specifies column order
# {elem[0]} : {elem[1]} displays keys column first
superfoods.sort{|a,b| a[0]<=>b[0]}.each { |elem|
puts "#{elem[0]}: #{elem[1]}" # keys first
}
puts
puts "KEYS COLUMN FIRST in REVERSE ALPHA"
superfoods.sort{|a,b| b[0]<=>a[0]}.each { |elem|
puts "#{elem[0]}: #{elem[1]}" # keys first
}
puts
puts "VALUES COLUMN FIRST in ALPHA ORDER"
superfoods.sort{|a,b| a[1]<=>b[1]}.each { |elem|
puts "#{elem[1]}: #{elem[0]}" # values first
}
puts
puts "VALUES COLUMN FIRST in REVERSE ALPHA"
superfoods.sort{|a,b| b[1]<=>a[1]}.each { |elem|
puts "#{elem[1]}: #{elem[0]}" # values first
}
puts
puts "VALUES COLUMN FIRST in REVERSE ALPHA, COUNTER VARS TO J,K"
# instead of |a,b| counters vars changed to |j,k| just to demonstrate they are arbitrary
# | j,k | is range, j[ ] and k[ ] are counters-identifiers
superfoods.sort{|j,k| k[1]<=>j[1]}.each { |elem|
puts "#{elem[1]}: #{elem[0]}" # values first
}
puts
# end ruby hash sorting tutorial
# END COPY AND PASTE HERE