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Have a hash:
h = {:a => "val1", :b => "val2", :c => "val3"} I can refer to the hash value:
h[:a], h[:c] but I would like to refer by numeric index:
h[0] => val1 h[2] => val3 Is it possible?
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A Hash is a collection of key-value pairs. It is similar to an Array , except that indexing is done via arbitrary keys of any object type, not an integer index.
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.
An explanation, why there are no examples with integers as Hash-keys. Hash-keys have (most of the times) a meaning. It may be an attribute name and its value (e.g. :color => 'red' ...). When you have an integer as a key, your semantic may be 'first, second ...' (1).
In Ruby, Hash is a collection of unique keys and their values. Hash is like an Array, except the indexing is done with the help of arbitrary keys of any object type. In Hash, the order of returning keys and their value by various iterators is arbitrary and will generally not be in the insertion order.
Online Hash Calculator. Online Hash Calculator lets you calculate the cryptographic hash value of a string or file. Multiple hashing algorithms are supported including MD5, SHA1, SHA2, CRC32 and many other algorithms.
Hash indexes are one of many ways to organize data in a database. They work by taking input and using it as a key for storage on a disk. These keys, or hash values, can be anything from string lengths to characters in the input. Hash indexes are most commonly used when querying specific inputs with specific attributes.
Hash Calculator Online Hash Calculator Online lets you calculate the cryptographic hash value of a string or file. Multiple hashing algorithms are supported including MD5, SHA1, SHA2, CRC32 and many other algorithms.
The three different ways we can get elements by index in a HashSet is by: Access elements by index. HashSet contains: [Geek, Geeks, For, Welcome, To] Element at index 3 is: Welcome HashSet contains: [Geek, Geeks, For, Welcome, To] Element at index 3 is: Welcome HashSet contains: [Geek, Geeks, For, Welcome, To] Element at index 3 is: Welcome
h.values will give you an array requested.
> h.values # ⇒ [ # [0] "val1", # [1] "val2", # [2] "val3" # ] UPD while the answer with h[h.keys[0]] was marked as correct, I’m a little bit curious with benchmarks:
h = {:a => "val1", :b => "val2", :c => "val3"} Benchmark.bm do |x| x.report { 1_000_000.times { h[h.keys[0]] = 'ghgh'} } x.report { 1_000_000.times { h.values[0] = 'ghgh'} } end # # user system total real # 0.920000 0.000000 0.920000 ( 0.922456) # 0.820000 0.000000 0.820000 ( 0.824592) Looks like we’re spitting on 10% of productivity.
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