Getting a list of keys
In order to minimize effort on dictionary maintenance Tcl has provided the dict keys command to return a list of keys that exist within a dictionary. The syntax is as follows:
dict keys dictionaryValue pattern
How to do it…
In the following example we will create a dictionary containing a collection of key/value pairs and then using the dict keys command obtain a list of valid keys. Return values from the commands are provided for clarity. Enter the following command:
% set test [dict create 1 John 2 Mary 3 Paul] 1 John 2 Mary 3 Paul % dict keys $test 1 2 3
How it works…
The dict keys command returns a list of keys that exists within the dictionary referenced by dictionaryValue. If a pattern is supplied, only those keys that match are returned.
