ASC: The Code Whisperer
Ever wondered what secret codes your computer uses to represent letters and symbols? The ASC function is your backstage pass to this hidden world of character codes! It takes any single character and reveals its corresponding numerical value in the Commodore ASCII table. Think of it as a translator between human language and computer language.
Syntax
ASC(<string>)
Where:
- <string>: The string containing the character you want to decode. ASC only looks at the first character in the string.
Applications
The ASC function shines when:
- You need to compare characters based on their alphabetical order (since A has a lower ASCII code than B).
- You're creating input validation routines to check if characters are letters, numbers, or symbols.
- You want to manipulate characters based on their numerical values (e.g., converting lowercase to uppercase).
Code Examples
1. Revealing the Secret Code:
10 A$="H" :rem A$ holds the letter 'H'
20 PRINT ASC(A$) :rem Output: 72 (ASCII code for 'H')
This simple example shows how ASC takes a character and reveals its numerical representation.
2. Checking for a Letter:
10 INPUT "Enter a letter or number: "; C$ :rem C$ holds a single letter
20 IF ASC(C$)>=65 AND ASC(C$)<=90 THEN PRINT "Uppercase letter"
30 IF ASC(C$)>=48 AND ASC(C$)<=57 THEN PRINT "Number"
This snippet checks if the entered character falls within the ASCII ranges for uppercase or lowercase letters.
3. Simple Encryption:
10 INPUT "Enter a message: "; M$ :rem M$ is the original message
20 FOR I=1 TO LEN(M$) :rem Iterate through each character in M$
30 C$=MID$(M$,I,1) :rem Get one character at a time into C$
40 PRINT CHR$(ASC(C$)+1); :rem Print next character in ASCII table
50 NEXT
This example shifts each character in the message one position forward in the ASCII table, creating a basic encryption.
ASC in the Wild: Custom Character Sets
Imagine you're designing a unique font for your Commodore 64 game. ASC lets you map each custom character to a specific ASCII code. This way, you can use the CHR$ function to display your custom characters in the game.
Unlock the mysteries of character codes with the ASC function! It's your key to understanding the language of computers and creating more versatile programs. Start experimenting with ASC and see what amazing things you can create!
