> I've a feeling one of the built in string formatting methods (sprintf
> or format) will do this, but I can't find a reference offhand.
The method is #formatWith:
e.g. 'hello %1!03u!' formatWith: 1
There are many other options using the printf format String that contains
the text to be printed.
see:
http://www.cplusplus.com/ref/cstdio/sprintf.htmlThe format tags follow this prototype:
%[flags][width][.precision][modifiers]type
where type is the most significant and defines how the value will be printed:
type Output Example
c
Character a
d or i
Signed decimal integer 392
e
Scientific notation (mantise/exponent) using e character 3.9265e2
E
Scientific notation (mantise/exponent) using E character 3.9265E2
f
Decimal floating point 392.65
g
Use shorter %e or %f 392.65
G
Use shorter %E or %f 392.65
o
Signed octal 610
s
String of characters sample
u
Unsigned decimal integer 7235
x
Unsigned hexadecimal integer 7fa
X
Unsigned hexadecimal integer (capital letters) 7FA
p
Address pointed by the argument B800:0000
n
Nothing printed. The argument must be a pointer to integer where the
number of characters written so far will be stored.
the other flags, width, .precision and modifiers sub-parameters are
optional and follow these specifications:
flags
meaning
-
Left align within the given width. (right align is the default).
+
Forces to preceed the result with a sign (+ or -) if signed type. (by
default only - (minus) is printed).
blank
If the argument is a positive signed value, a blank is inserted before
the number.
#
Used with o, x or X type the value is preceeded with 0, 0x or 0X respectively
if non-zero.
Used with e, E or f forces the output value to contain a decimal point
even if only zeros follow.
Used with g or G the result is the same as e or E but trailing zeros
are not removed.
width
meaning
number
Minimum number of characters to be printed. If the value to be printed
is shorter than this number the result is padded with blanks. The value is
never truncated even if the result is larger.
0number
Same as above but filled with 0s instead of blanks.
*
The width is not specified in the format string, it is specified by
an integer value preceding the argument thas has to be formatted.
.precision
meaning
.number
for d, i, o, u, x, X types: precision specifies the minimum number of
decimal digits to be printed. If the value to be printed is shorter than
this number the result is padded with blanks. The value is never truncated
even if the result is larger.(if nothing specified default is 1).
for e, E, f types: number of digits to be printed after de decimal point.
(if nothing specified default is 6).
for g, G types : maximum number of significant numbers to be printed.
for s type: maximum number of characters to be printed. (default is to
print until first null character is encountered).
for c type : (no effect).
modifier
meaning (affects on how arguments are interpreted by the function)
h
argument is interpreted as short int (integer types).
l
argument is interpreted as long int (interger types) or double (floating
point types).
L
argument is interpreted as long double (floating point types).
argument(s)
Optional parameter(s) that contain the data to be inserted instead of
% tags specified in format parameter. There must be the same number of these
parameter than the number format tags.
Locked
