ABS
| BASIC keyword | |
| Keyword: | ABS |
| Abbreviation: | A Shift+B |
| Type: | Function |
| Token code: | 182/$B6 |
| Handling routine in BASIC ROM: |
48216–48218 $BC58–BC5A |
| List of all BASIC keywords | |
Remark: This article describes the BASIC command ABS in BASIC V2 at the Commodore 64.
Type: Numeric Function General Programming-Syntax: ABS(<numeric-expression>)
ABS evaluates to the absolute value (value without the sign) of the given numeric term.
The numeric parameter has to be a floating point number. If the term is not numeric, the BASIC error ?TYPE MISMATCH ERROR occurs.
When the numeric argument is absent, it displays a ?SYNTAX ERROR.
Examples[edit | edit source]
Parameters[edit | edit source]
PRINT ABS(-10) (Screen: 10) PRINT ABS(-10-11+5) (Screen: 16) PRINT ABS("Text") (Screen: ?TYPE MISMATCH ERROR) PRINT ABS() (Screen: ?SYNTAX ERROR)
Re-implementing the SGN function[edit | edit source]
The ABS function is helpful to re-implement the SGN function:
100 DEF FN SG(X)=X/(ABS(X)-(X=0)) 200 FOR I=-10 TO 10 STEP 10 210 PRINT I,SGN(I),FN SG(I) 220 NEXT
The first column shows the value to be tested, the second column the built-in SGN function value and the third column the value of the recreated function.
Following output will be shown
-10 -1 -1 0 0 0 10 1 1
The new defined function FN SG(X) covers also the special case for value 0 by using the additional term -(X=0) (gives the value 1) to avoid a division by zero condition.
ABS | AND | ASC | ATN | CHR$ | CLOSE | CLR | CMD | CONT | COS | DATA | DEF | DIM | END | EXP | FN | FOR | FRE | GET | GET# | GOSUB | GOTO | IF | INPUT | INPUT# | INT | LEFT$ | LEN | LET | LIST | LOAD | LOG | MID$ | NEW | NEXT | NOT | ON | OPEN | OR | PEEK | π | POKE | POS | PRINT | PRINT# | READ | REM | RESTORE | RETURN | RIGHT$ | RND | RUN | SAVE | SGN | SIN | SPC | SQR | STATUS/ST | STEP | STOP | STR$ | SYS | TAB | TAN | THEN | TIME/TI | TIME$/TI$ | TO | USR | VAL | VERIFY | WAIT
