Indexed Array and Key-Based Array Properties

The VMware vSphere data structures include array properties, which can be indexed arrays or key-based arrays.

• Indexed arrays are accessed by using an index integer. Indexed arrays are used for arrays of data types whose positions in the array do not change. For example, the roleList property of the AuthorizationManager managed object is an array of authorization roles. Adding a new role to the array does not change the position of existing elements in the array.
• Key-based arrays are used for information whose position is subject to change. A key-based array (same basic concept as a Perl hash or a Python dictionary) uses a unique, unchanging value as a key to access an element’s value.

  Typically, the key is a string, but integers can also be used. For example, Event arrays use integers as keys.

  The vSphere management object model uses key-based arrays to track managed object references. The contents of a key-based array property are accessed by the value of either the key property or, in the case of a managed object reference, its value property. The value of these fields is unique across all of the components of an array.

  Nested properties can also refer to entries in a key-based array. For example, a.b.c["xyz"] refers to the property c that has the key value of xyz.