dynamic creation of hash

[MikeShank]

Hi,
How would I or is it possible to:

 file.each_line do |line|
    line_array = line.split("\t")
    line_array[0] = key
    line_array[1] = value
 # tried this, didnt work
    my_hash[key] = []
    my_hash[key] << value
 end 

What I'm looking to end up with is something like this:

 {"key1"=>["value1", "value1"]}
 {"key2"=>["value1", "value1", "value3", "value4"]}
 {"key3"=>["value1"]} 

thanks for any help

[sweatje]

how about:

>> my_hash = {}
=> {}
>> my_hash['key'] = ['value1']
=> ["value1"]
>> my_hash['key2'] = ['val2','val3']
=> ["val2", "val3"]
>> my_hash
=> {"key2"=>["val2", "val3"], "key"=>["value1"]}

[MikeShank]

sweatje, basically that's what I'm trying to achieve, kind of. But I'm looking to append values to the array not overwrite them with each iteration based on the hash key

[sweatje]

Appending should work fine, once there is an array there:

>> my_hash['key2'] << 'val4'
=> ["val2", "val3", "val4"]
>> my_hash
=> {"key2"=>["val2", "val3", "val4"], "key"=>["value1"]}

[MikeShank]

Right, I guess my problem is when I assign:
my_hash[key] = []

inside of the do block, it overwrites. How can I use a dynamic hash key and append values to it?

[sweatje]

perhaps

my_hash[key] = [] unless my_hash.key? key
my_hash[key] << new_val

[MikeShank]

Thanks Jason, that's exactly what i was looking for.