Undefined values: Difference between revisions
m
→{{header|J}}
m (→{{header|J}}) |
m (→{{header|J}}) |
||
Line 392:
0 _1</lang>
From this we can infer that <code>foo</code> has a definition (and its definition is a noun, since 0 is the syntactic [http://www.jsoftware.com/help/dictionary/dx004.htm name class] for nouns), and we can also infer that <code>bar</code> does not have a definition.
This task also asked that we ''identify and exercise .. mechanisms for ... manipulating a variable's value's status as being undefined''. So: a name can be made to be undefined using the verb <code>erase</code>. The undefined status can be removed by assigning a value to the name.
| |||