The FORMAT$() function converts a format string and a list of values into a single string. (Nearly identical to sprintf() in C, but with some of the formatting codes blocked)
Rather than using multiple STR$, HEX$, or BIN$ functions, and combining strings, you can use FORMAT$ to make your code neater.
For example, if you're displaying a list of names and highscores, and you want the rows to line up:
GPUTCHR 0,0," "*(8-LEN(NAME$[I]))+NAME$[I]+" : "+STR$(HIGHSCORE[I])
'can be...
GPUTCHR 0,0,FORMAT$("%8S : %D",NAME$[I],HIGHSCORE[I])FORMAT$ can accept an unlimited* number of values (even 0!).
string$ = FORMAT$( formatString$, values ...
)
formatString$ is a string containing normal text and formatting codes.
Formatting codes start with
% and end with a letter that controls the type. They can also have optional flags between the % and the letter.
"
%" can be inserted into the output by escaping it:
%%
Arguments:
% [
flags ] [
length ] [ .
precision ]
type
Type:
Required.
S - string
D - decimal integer
X - hexadecimal integer
B - binary integer
F - floating point
Not case sensitive.
Values are truncated (rounded towards 0) when displayed as an integer.
When converting values to integers, FORMAT$ will throw an overflow error if the value is too big or too small.
Length:
Optional. The minimum length of the inserted value.
By default, space padding will be added to the left side if the value is too short.
Flags:
Optional.
- adds a space before positive numbers. (Only works with %D and %F.) (ignored if the + flag is present)
+ - adds a + sign before positive numbers. (Only works with %D and %F.)
- - adds padding to the right side instead of the left side.
0 - uses
0s for padding instead of spaces (unless the
- flag is present or if the value is
inf or
nan).
Precision:
Optional. (Only works with %F and %S)
Numbers will be rounded to this number of decimal places. If precision is omitted, %F defaults to 6 decimal places.
If the last digit has only a 5 after it, it will be rounded unpredictably.
Using 0 will not display the decimal point, and rounds numbers ending in .5 to the nearest even number.
In %S, the precision setting behaves differently. It will truncate a string to that length if it is longer (rather than extending it like
length does).
You can force a string to be a certain length by setting both
length and
precision using the format code
%n.nS where
n is the length you want.
