1. Computing

Building Hashes

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Hash Literals

This is by far the most common way to put data into a Hash. This is best suited for small hashes, one-off parameters to methods, or struct-like objects. The most common way to do this is the "rocket" syntax.


#!/usr/bin/env ruby

hash = {
 :key => 'value',
 :key2 => 'value2'
}

p hash

This is the easiest way to do this in all code up to version 1.9.2. There, a new syntax was introduced. And while this syntax works on 1.9.2, it won't work on earlier versions, so be aware before using it.


#!/usr/bin/env ruby

hash = {
 key: 'value',
 key2: 'value2'
}

p hash

This is a much cleaner syntax, and reduces the amount of "line noise" (AKA special characters) in your code. However, it makes the assumption that your key is going to be a symbol. If you're using any other objects as your keys (numbers, for example), you can't use this syntax.

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