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I have a hash like
{:key1 => "value1", :key2 => "value2"}
And I have a variable k which will have the value as 'key1' or 'key2'.
I want to get the value of k into a variable v.
Is there any way to achieve this with out using if or case? A single line solution is preferred. Please help.
404
In Ruby, the values in a hash can be accessed using bracket notation. After the hash name, type the key in square brackets in order to access the value.
Simply pressing alt and 3 at the same time will insert a # hash symbol into your text in any application. This shortcut will work with all versions of Mac OS X whether you have a Macbook, Air or an iMac. In most cases Apple has decided to replace this key with a symbol of the local currency.
Iterating over a Hash You can use the each method to iterate over all the elements in a Hash. However unlike Array#each , when you iterate over a Hash using each , it passes two values to the block: the key and the value of each element.
A Hash is a dictionary-like collection of unique keys and their values. Also called associative arrays, they are similar to Arrays, but where an Array uses integers as its index, a Hash allows you to use any object type. Hashes enumerate their values in the order that the corresponding keys were inserted.
Convert the key from a string to a symbol, and do a lookup in the hash.
hash = {:key1 => "value1", :key2 => "value2"} k = 'key1' hash[k.to_sym] # or iow, hash[:key1], which will return "value1" Rails uses this class called HashWithIndifferentAccess that proves to be very useful in such cases. I know that you've only tagged your question with Ruby, but you could steal the implementation of this class from Rails' source to avoid string to symbol and symbol to string conversions throughout your codebase. It makes the value accessible by using a symbol or a string as a key.
hash = HashWithIndifferentAccess.new({:key1 => "value1", :key2 => "value2"}) hash[:key1] # "value1" hash['key1'] # "value1" If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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