Association

An Association represents a binary relation between two objects, called the key and the value.

Note:

Technically, the semantics of the magnitude comparing operations are different for Associations, because the messages <, <=, >, and >= are defined in terms of the key only, while the = message is defined in terms of both the key and the value. This means, for example, that <= is not the "logical or" of < and =. Despite this, Association has been grouped with the magnitude classes because that is where it is traditionally implemented in the Smalltalk environment.

Accessing

key, key:, key:value:, value, value:

Porting tip:

Both VA Smalltalk and Objectworks\Smalltalk define the = message in terms of both the key and the value. Smalltalk/V defines = in terms of the key only. Smalltalk/V does not provide the message key:value:.

Creating instances (Association class)

key:value:

Creating instances (Object)

->

Porting tip:

Although not included in the Blue Book, this convenience method is provided by most other Smalltalk implementations.