CHARSUB()
Subtracts corresponding ASCII value of two strings
Syntax
CHARSUB( <[@]cString1>, <cString2>) --> cSubString
Arguments
<[@]cString1> first string <cString2> second string
Returns
<cSubString> string with subtracted ASCII values
Description
The CHARSUB() function constructs a new string from the two strings passed as parameters. To do this, it subtracts the ASCII values of the corresponding characters of both strings and places a character in the resulting string whose ASCII value equals to that difference (modulo 256). If the first string is passed by reference, the resulting string is stored in <cString1>, too. By setting the CSETREF()-switch to .T., the return value can be omitted. If <cString2> is shorter than <cString1> and the last character of <cString2> has been processed, the function restarts with the first character of <cString2>.
Examples
? charsub( "012345678", Chr( 1 ) ) // --> "/01234567"
? charsub( "123456789", Chr( 255 ) ) // --> "23456789:"
? charsub( "9999", Chr( 0 ) + Chr( 1 ) + Chr( 2 ) + Chr( 3 ) ) // --> "9876"
Tests
charsub( "123456789", Chr( 1 ) ) == "012345678"
charsub( "123456789", Chr( 1 ) + Chr( 2 ) ) == "002244668"
charsub( "012345678", Chr( 255 ) ) == "123456789"
charsub( "012345678", Chr( 255 ) + Chr( 254 ) ) == "133557799"
Compliance
CHARSUB() is a new function that is only available in Harbour’s CT3 lib.
Platforms
All
Files
Source is charop.c, library is ct3.
Seealso
CHARADD(), CHARAND(), CHARNOT(), CHAROR(), CHARXOR(), CHARSHL(), CHARSHR(), CHARRLL(), CHARRLR(), CSETREF()