---
name: "Symbol"
section: "3"
platform: "linux"
package: "objc-poc"
version: "3.1.3-2"
release: "Debian 2.2 (Potato)"
platforms: ["linux"]
url: "https://new.carta.tech/Symbol"
---

# Symbol(3)

## Symbol

**Inherits from:**

CAObject

## Class Description

Maturity Index : Relatively Mature

For symbols created with the factory method  **str:** , the first character of the  **str** of the symbol object must be a letter.  Subsequent characters can be letters or digits.  Whitespace or control characters are not allowed.

Using the factory method  **chars:count:** , it's possible to use arbitrary C strings as the value of the symbol; in this case  **Symbol** just acts like a regular Objective C String class.  If you intend to use the object as a mathematical symbol, it's not advised to do this as you might incorrectly interpret spaces etc. as mathematical operators.

## Method types

**Creation**

\* str:\
 \* chars:count:\
 \* copy\
 \* deepCopy\
 \* release

**Identity**

\* str\
 \* str:\
 \* hash\
 \* isEqual:\
 \* compare:\
 \* isLetter

**Printing**

\* printOn:

## Methods

str:

\+ **str** :(STR) *aString*

Creates a new symbol, and sets its value to a copy of  *aString* .  Returns  **nil** if  *aString* is not suited as value for a symbol (when the first letter is not a letter, for instance).

chars:count:

\+ **chars** :(char \*) *aBuffer* **count** :(int) *numChars*

Creates a new symbol, and sets its value to a copy of the first  *numChars* characters of  *aBuffer* .  For this method, there are no restrictions on the C string being used.

copy

\- **copy**

Returns a new symbol object.  Copies the string.

deepCopy

\- **deepCopy**

Equivalent to  **copy** .

release

\- **release**

Frees the memory for the string value.

str

\- ( STR ) **str**

Returns the string value of the symbol.  The first character is a letter, subsequent characters can be alphanumeric.

str:

\- **str** :(STR) *aString*

Creates a new symbol, and sets its value to a copy of  *aString* .  Returns  **nil** if  *aString* is not suited as value for a symbol.

hash

\- ( unsigned ) **hash**

Returns a hash value based upon the string.

isEqual:

\- ( BOOL ) **isEqual** : *b*

Returns YES if the str's of both objects are equal.

compare:

\- ( int ) **compare** : *b*

Compares the str's of both objects.

isLetter

\- ( BOOL ) **isLetter**

Whether the symbol consists of just one character (and hence, is a letter, not a digit).

printOn:

\- **printOn** :(IOD) *aFile*

Prints the symbol to  *aFile* .