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()