Basics

system

• Chr(b), where b is a byte, it returns an ascii character

  See https://www.freepascal.org/docs-html/rtl/system/chr.html

• Ord(), see https://www.freepascal.org/docs-html/rtl/system/ord.html

sysutils

• IntToStr(i) to convert an integer to a string

  See https://www.freepascal.org/docs-html/rtl/sysutils/inttostr.html

• StrToInt(s) to convert a string to an integer

  See https://www.freepascal.org/docs-html/rtl/sysutils/strtoint.html. If the conversion failed, the above link gives an example about how to catch the exception.

  See also StrToInDef, which returns a specified default value on conversion failure.

• Format(), similar to sprintf() in C/C++.

  See https://www.freepascal.org/docs-html/rtl/sysutils/format.html

Commonly used controls

Label.Caption := "hello"