networktestinggenius.tk

Dictionaries 

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The dict commands implement a paired list data structure in which a key and value are guaranteed to maintain their relationship and order of the indices is maintained. 

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 This is like a merger of an associative array (key/value pairs) and the list (ordered data) structures. An associative array guarantees that the value associated with a given index won't change (unless an application changes it) but doesn't guarantee the order of indices. A list guarantees that the elements won't change order (again unless your code changes things) but doesn't show how one value is related to another. 

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 The dict command has several subcommands. The critical ones are: 
 

dict create ?key val? ?key val? 
Create a new dict and return values to be assigned to a variable.
 You may have zero or more key and value pairs, but the every key must have a value. 

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dict set dictName key val  
Assign a new key/value pair to the dictionary named dictName. You can only assign values to a single key at a time. If there are multiple key/value pairs, you must be creating a new index, and the values will be treated as nested dicts. See the lesson on nested dicts for more information. Note that set uses a variable name, not the value. 

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dict get $dictName key 
Return the value associated with the key in the dictionary. Only one key can be queried at a time. 

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dict size $dictName  
Return the number of key/value pairs in the dictionary. 

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dict keys $dictName ?pattern? 
Return a list of the keys in the dictionary. Optionally, only the keys that match a pattern. 

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dict values $dictName 
Return a list of the patterns in a dictionary. Optionally, only the values that match a pattern.