ruby hash
A Hash stores information in the form of a key value pair.
KEY VALUE
yunnan kunming
sichuan chengdu
guizhou guiyang
In the hash given above, the key is the country name and the value is the city of the province.
hash = {
"yunnan" => "kunming ",
"sichuan" => "chengdu",
"guizhou" => "guiyang",
}
puts hash
puts hash["yunnan"]
// Add Data to a Hash Using Key
hash.merge!({"guangdong" => "guangzhou"})
puts hash
hash["nanning"] = "guangxi"
Hash provides the method keys to list all keys from a hash.
hash = {
"yunnan" => "kunming ",
"sichuan" => "chengdu",
"guizhou" => "guiyang",
}
all_keys = hash.keys
puts all_keys
Just like Array and Range, Hash also supports each do.
hash = {
"yunnan" => "kunming ",
"sichuan" => "chengdu",
"guizhou" => "guiyang",
}
hash.each do |key, value|
puts "city of #{key} is #{value}"
end