Function

CFStringGetCharacterAtIndex(_:_:)

Returns the Unicode character at a specified location in a string.

Declaration

func CFStringGetCharacterAtIndex(_ theString: CFString!, _ idx: CFIndex) -> UniChar

Parameters

theString

The string from which the Unicode character is obtained.

idx

The position of the Unicode character in the CFString.

Return Value

A Unicode character.

Discussion

This function is typically called in a loop to fetch the Unicode characters of a string in sequence or to fetch a character at a known position (first or last, for example). Using it in a loop can be inefficient, especially with longer strings, so consider the CFStringGetCharacters(_:_:_:) function or the in-line buffer functions (CFStringInitInlineBuffer(_:_:_:) and CFStringGetCharacterFromInlineBuffer(_:_:)) as alternatives.

See Also

Accessing Characters

func CFStringCreateExternalRepresentation(CFAllocator!, CFString!, CFStringEncoding, UInt8) -> CFData!

Creates an “external representation” of a CFString object, that is, a CFData object.

func CFStringGetBytes(CFString!, CFRange, CFStringEncoding, UInt8, Bool, UnsafeMutablePointer<UInt8>!, CFIndex, UnsafeMutablePointer<CFIndex>!) -> CFIndex

Fetches a range of the characters from a string into a byte buffer after converting the characters to a specified encoding.

func CFStringGetCharacters(CFString!, CFRange, UnsafeMutablePointer<UniChar>!)

Copies a range of the Unicode characters from a string to a user-provided buffer.

func CFStringGetCharactersPtr(CFString!) -> UnsafePointer<UniChar>!

Quickly obtains a pointer to the contents of a string as a buffer of Unicode characters.

func CFStringGetCharacterFromInlineBuffer(UnsafeMutablePointer<CFStringInlineBuffer>!, CFIndex) -> UniChar

Returns the Unicode character at a specific location in an in-line buffer.

func CFStringGetCString(CFString!, UnsafeMutablePointer<Int8>!, CFIndex, CFStringEncoding) -> Bool

Copies the character contents of a string to a local C string buffer after converting the characters to a given encoding.

func CFStringGetCStringPtr(CFString!, CFStringEncoding) -> UnsafePointer<Int8>!

Quickly obtains a pointer to a C-string buffer containing the characters of a string in a given encoding.

func CFStringGetLength(CFString!) -> CFIndex

Returns the number (in terms of UTF-16 code pairs) of Unicode characters in a string.

func CFStringGetPascalString(CFString!, StringPtr!, CFIndex, CFStringEncoding) -> Bool

Copies the character contents of a CFString object to a local Pascal string buffer after converting the characters to a requested encoding.

func CFStringGetPascalStringPtr(CFString!, CFStringEncoding) -> ConstStringPtr!

Quickly obtains a pointer to a Pascal buffer containing the characters of a string in a given encoding.

func CFStringGetRangeOfComposedCharactersAtIndex(CFString!, CFIndex) -> CFRange

Returns the range of the composed character sequence at a specified index.

func CFStringInitInlineBuffer(CFString!, UnsafeMutablePointer<CFStringInlineBuffer>!, CFRange)

Initializes an in-line buffer to use for efficient access of a CFString object's characters.

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