Asc

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Asc

Returns the character code at a position in a string.

Syntax

Declare Function Asc ( ByRef str As Const String, ByVal position As Integer = 1 ) As ULong
Declare Function Asc ( ByVal str As Const ZString Ptr, ByVal position As Integer = 1 ) As ULong
Declare Function Asc ( ByVal str As Const WString Ptr, ByVal position As Integer = 1 ) As ULong

Parameters

• str
• position

Description

If str is a String or a ZString, the UByte value at that position is returned. This will be a 7-bit ASCII code, or even a 8-bit character value from some code-page, depending on the string data stored in str.

If str is a WString, the UShort (Windows) or ULong (Linux and macOS) value at that position is returned. This will be a 16bit value on Windows (WStrings use UTF16 there), or a 32bit value on Linux and macOS (WStrings use UTF32 there).

The function returns zero (0) if the string is a zero length string, position is less than one (1), or position is greater than the number of characters in str.

Chr performs the opposite function for ASCII strings, while WChr is the opposite for Unicode strings, returning a string containing the character represented by the code passed as an argument.

Return Value

The raw character value stored at position in str.
If both str and position can be evaluated at compile time (like Asc("a") or Asc(chr(97)) or Asc("abc", 2) ...), the value is returned in a UInteger result, otherwise in a ULong result.

Remarks

Usage

result = Asc( str [, position ] )

Platform Differences

• DOS does not support the wide-character string version of Asc.

Differences from QB

• The optional position argument is new to FreeBASIC.
• QB does not support the wide-character string version of Asc

See also

• Chr
• Str
• Val

Examples

Print "the ascii code of 'a' is:"; Asc("a")

Print "the ascii code of 'b' is:"; Asc("abc", 2)

will produce the output:

the ascii code of 'a' is: 97
the ascii code of 'b' is: 98

Unicode example (Note to documentation editors: don't put inside %%(qbasic) markers or the Russian text will disappear!)

dim a as wstring * 12

a = "Привет, мир"

print "the Unicode of the second char of " & a & " is: " & asc(a, 2)

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Category: String Functions
Kind: function

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Reproduced from the FreeBASIC Wiki Manual under the GNU Free Documentation License 1.3 — with no Invariant Sections, no Front-Cover Texts and no Back-Cover Texts. Copyright © the FreeBASIC project and wiki contributors. See License.