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sprintf
Return a formatted string
Description
string sprintf
( string $format
[, mixed $args
[, mixed $...
]] )
Parameters
-
format
-
The format string is composed of zero or more directives:
ordinary characters (excluding %) that are
copied directly to the result, and conversion
specifications, each of which results in fetching its
own parameter. This applies to both sprintf
and printf.
Each conversion specification consists of a percent sign
(%), followed by one or more of these
elements, in order:
-
An optional sign specifier that forces a sign
(- or +) to be used on a number. By default, only the - sign is used
on a number if it's negative. This specifier forces positive numbers
to have the + sign attached as well, and was added in PHP 4.3.0.
-
An optional padding specifier that says
what character will be used for padding the results to the
right string size. This may be a space character or a
0 (zero character). The default is to pad
with spaces. An alternate padding character can be specified
by prefixing it with a single quote (').
See the examples below.
-
An optional alignment specifier that says
if the result should be left-justified or right-justified.
The default is right-justified; a -
character here will make it left-justified.
-
An optional number, a width specifier
that says how many characters (minimum) this conversion should
result in.
-
An optional precision specifier in the form
of a period (`.') followed by an optional decimal digit string
that says how many decimal digits should be displayed for
floating-point numbers. When using this specifier on a string,
it acts as a cutoff point, setting a maximum character limit to
the string.
-
A type specifier that says what type the
argument data should be treated as. Possible types:
-
% - a literal percent character. No
argument is required.
-
b - the argument is treated as an
integer, and presented as a binary number.
-
c - the argument is treated as an
integer, and presented as the character with that ASCII
value.
-
d - the argument is treated as an
integer, and presented as a (signed) decimal number.
-
e - the argument is treated as scientific
notation (e.g. 1.2e+2).
The precision specifier stands for the number of digits after the
decimal point since PHP 5.2.1. In earlier versions, it was taken as
number of significant digits (one less).
-
E - like %e but uses
uppercase letter (e.g. 1.2E+2).
-
f - the argument is treated as a
float, and presented as a floating-point number (locale aware).
-
F - the argument is treated as a
float, and presented as a floating-point number (non-locale aware).
Available since PHP 4.3.10 and PHP 5.0.3.
-
g - shorter of %e and
%f.
-
G - shorter of %E and
%f.
-
o - the argument is treated as an
integer, and presented as an octal number.
-
s - the argument is treated as and
presented as a string.
-
u - the argument is treated as an
integer, and presented as an unsigned decimal number.
-
x - the argument is treated as an integer
and presented as a hexadecimal number (with lowercase
letters).
-
X - the argument is treated as an integer
and presented as a hexadecimal number (with uppercase
letters).
Variables will be co-erced to a suitable type for the specifier:
Type Handling
| Type |
Specifiers |
| string |
s |
| integer |
d,
u,
c,
o,
x,
X,
b
|
| double |
g,
G,
e,
E,
f,
F
|
Warning
Attempting to use a combination of the string and width specifiers with character sets that require more than one byte per character may result in unexpected results
The format string supports argument numbering/swapping. Here is an
example:
Example #1 Argument swapping
<?php
$num = 5;
$location = 'tree';
$format = 'There are %d monkeys in the %s';
echo sprintf($format, $num, $location);
?>
This will output "There are 5 monkeys in the tree". But
imagine we are creating a format string in a separate file,
commonly because we would like to internationalize it and we
rewrite it as:
Example #2 Argument swapping
<?php
$format = 'The %s contains %d monkeys';
echo sprintf($format, $num, $location);
?>
We now have a problem. The order of the placeholders in the
format string does not match the order of the arguments in the
code. We would like to leave the code as is and simply indicate
in the format string which arguments the placeholders refer to.
We would write the format string like this instead:
Example #3 Argument swapping
<?php
$format = 'The %2$s contains %1$d monkeys';
echo sprintf($format, $num, $location);
?>
An added benefit here is that you can repeat the placeholders without
adding more arguments in the code. For example:
Example #4 Argument swapping
<?php
$format = 'The %2$s contains %1$d monkeys.
That\'s a nice %2$s full of %1$d monkeys.';
echo sprintf($format, $num, $location);
?>
When using argument swapping, the n$
position specifier must come immediately
after the percent sign (%), before any other
specifiers, as shown in the example below.
Example #5 Position specifier with other specifiers
<?php
$format = 'The %2$s contains %1$04d monkeys';
echo sprintf($format, $num, $location);
?>
The above example will output:
The tree contains 0005 monkeys
Note:
Attempting to use a position specifier greater than
PHP_INT_MAX will result in
sprintf generating warnings.
Warning
The c type specifier ignores padding and width
-
args
-
-
...
-
Return Values
Returns a string produced according to the formatting string
format.
Examples
Example #6 printf: various examples
<?php
$n = 43951789;
$u = -43951789;
$c = 65; // ASCII 65 is 'A'
// notice the double %%, this prints a literal '%' character
printf("%%b = '%b'\n", $n); // binary representation
printf("%%c = '%c'\n", $c); // print the ascii character, same as chr() function
printf("%%d = '%d'\n", $n); // standard integer representation
printf("%%e = '%e'\n", $n); // scientific notation
printf("%%u = '%u'\n", $n); // unsigned integer representation of a positive integer
printf("%%u = '%u'\n", $u); // unsigned integer representation of a negative integer
printf("%%f = '%f'\n", $n); // floating point representation
printf("%%o = '%o'\n", $n); // octal representation
printf("%%s = '%s'\n", $n); // string representation
printf("%%x = '%x'\n", $n); // hexadecimal representation (lower-case)
printf("%%X = '%X'\n", $n); // hexadecimal representation (upper-case)
printf("%%+d = '%+d'\n", $n); // sign specifier on a positive integer
printf("%%+d = '%+d'\n", $u); // sign specifier on a negative integer
?>
The above example will output:
%b = '10100111101010011010101101'
%c = 'A'
%d = '43951789'
%e = '4.39518e+7'
%u = '43951789'
%u = '4251015507'
%f = '43951789.000000'
%o = '247523255'
%s = '43951789'
%x = '29ea6ad'
%X = '29EA6AD'
%+d = '+43951789'
%+d = '-43951789'
Example #7 printf: string specifiers
<?php
$s = 'monkey';
$t = 'many monkeys';
printf("[%s]\n", $s); // standard string output
printf("[%10s]\n", $s); // right-justification with spaces
printf("[%-10s]\n", $s); // left-justification with spaces
printf("[%010s]\n", $s); // zero-padding works on strings too
printf("[%'#10s]\n", $s); // use the custom padding character '#'
printf("[%10.10s]\n", $t); // left-justification but with a cutoff of 10 characters
?>
The above example will output:
[monkey]
[ monkey]
[monkey ]
[0000monkey]
[####monkey]
[many monke]
Example #8 sprintf: zero-padded integers
<?php
$isodate = sprintf("%04d-%02d-%02d", $year, $month, $day);
?>
Example #9 sprintf: formatting currency
<?php
$money1 = 68.75;
$money2 = 54.35;
$money = $money1 + $money2;
// echo $money will output "123.1";
$formatted = sprintf("%01.2f", $money);
// echo $formatted will output "123.10"
?>
Example #10 sprintf: scientific notation
<?php
$number = 362525200;
echo sprintf("%.3e", $number); // outputs 3.625e+8
?>
See Also
- printf
- sscanf
- fscanf
- vsprintf
- number_format
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