ASC and CHR · Procedural

Build the idea

Start with the concept and its key vocabulary.

Key idea

Use OCR ASC/CHR and Python ord()/chr() in short string-processing programs.

ASC() converts one character into its numeric code, while CHR() performs the reverse conversion. Python calls these functions ord() and chr(). For the standard examples, A has code 65 and code 97 represents lowercase a.

Character code

A number used by a computer to represent a character.

ASC()

The OCR ERL operation that returns the numeric code of a character.

CHR()

The OCR ERL operation that returns the character represented by a numeric code.

ord() / chr()

The Python functions corresponding to OCR ASC() and CHR().

Keep these in mind

OCR ASC(character) maps to Python ord(character).
OCR CHR(number) maps to Python chr(number).
ASC returns a number; CHR returns one character.
A code can be adjusted with arithmetic before converting it back to a character.

Build the idea

Start with the concept and its key vocabulary.

Key idea

Use OCR ASC/CHR and Python ord()/chr() in short string-processing programs.

Character code

A number used by a computer to represent a character.

ASC()

The OCR ERL operation that returns the numeric code of a character.

CHR()

The OCR ERL operation that returns the character represented by a numeric code.

ord() / chr()

The Python functions corresponding to OCR ASC() and CHR().

Keep these in mind

OCR ASC(character) maps to Python ord(character).
OCR CHR(number) maps to Python chr(number).
ASC returns a number; CHR returns one character.
A code can be adjusted with arithmetic before converting it back to a character.