I need to parse the following input string into a hash table with the following format:
Input:
'1001=23;1001B=5;1002=0;1003=5;'
Output:
=> {'1001'=>23,'1001B'=>5,'1002'=>0,'1003'=>5}
My solution:
def parser input
output = {}
input.split(';').map {|ar| ar.split('=')}.each {|id, c| output[id]=c.to_i}
output
end
parser '1001=23;1001B=5;1002=0;1003=5;'
Any insight is appreciated.
You can make it a single expression by taking advantage of Hash[[key, value], …] (available since Ruby 1.9).
The function name could probably be improved.
When using String#split, I consider it good practice to limit the number of splits whenever a limit may be applicable. Here, you wouldn't be able to tolerate a second = sign within each key=value string, so you should use pair.split('=', 2).
def to_hash(str)
Hash[
str.split(';').map do |pair|
k, v = pair.split('=', 2)
[k, v.to_i]
end
]
end
Is this a method or a classmethod? since it's not using anything of the instance, it probably should be a classmethod. I'd write:
def self.parser(strval)
strval.split(';').map do |pair|
key, value = pair.split('=')
[key, value.to_i]
end.to_h
end
You can simplify what you have by using each rather than map and performing all operations in one block:
def parser input
output = {}
input.split(';')
.each do |s|
k,v = s.split('=')
output[k] = v.to_i
end
output
end
Further simplification is possible by using Enumerable#each_with_object:
def parser input
input.split(';')
.each_with_object({}) do |s,output|
k,v = s.split('=')
output[k]=v.to_i
end
end
Here's another way:
def parser input
input.split(/=|;/).each_slice(2)
.with_object({}) { |(k,v),h| h[k]=v.to_i }
end
