► |  | The Racket Reference

1 | Language Model
2 | Notation for Documentation
3 | Syntactic Forms
4 | Datatypes
5 | Structures
6 | Classes and Objects
7 | Units
8 | Contracts
9 | Pattern Matching
10 | Control Flow
11 | Concurrency and Parallelism
12 | Macros
13 | Input and Output
14 | Reflection and Security
15 | Operating System
16 | Memory Management
17 | Unsafe Operations
18 | Running Racket
| Bibliography
| Index

▼ | 4 | Datatypes

4.1 | Equality
4.2 | Booleans
4.3 | Numbers
4.4 | Strings
4.5 | Byte Strings
4.6 | Characters
4.7 | Symbols
4.8 | Regular Expressions
4.9 | Keywords
4.10 | Pairs and Lists
4.11 | Mutable Pairs and Lists
4.12 | Vectors
4.13 | Boxes
4.14 | Hash Tables
4.15 | Sequences and Streams
4.16 | Dictionaries
4.17 | Sets
4.18 | Procedures
4.19 | Void
4.20 | Undefined

On this page:

void?
void

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#### 4.19`` Void

The constant #<void> is returned by most forms and procedures that have a side-effect and no useful result.

The #<void> value is always eq? to itself.

> > procedure

> > (void? v) → boolean?

> v : any/c

Returns #t if v is the constant #<void>, #f otherwise.

> > procedure

> > (void v ...) → void?

> v : any/c

Returns the constant #<void>. Each v argument is ignored.
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