Show how to iterate over the key-value pairs of an associative array, and print each pair out.

Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.



See also

 Array
 Associative array: Creation, Iteration
 Collections
 Compound data type
 Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
 Linked list
 Queue: Definition, Usage
 Set
 Singly-linked list: Element definition, Element insertion, List Traversal, Element Removal
 Stack


BEGIN {
  a["hello"] = 1
  a["world"] = 2
  a["!"] = 3
 
  # iterate over keys, undefined order
  for(key in a) {
    print key, a[key]
  }
}