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sprintf
Return a formatted string
Description
string sprintf(string $format, mixed ...$values)
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.
A conversion specification follows this prototype:
%[argnum$][flags][width][.precision]specifier.
Argnum
An integer followed by a dollar sign $,
to specify which number argument to treat in the conversion.
Flags
| Flag |
Description |
- |
Left-justify within the given field width;
Right justification is the default
|
+ |
Prefix positive numbers with a plus sign
+; Default only negative
are prefixed with a negative sign.
|
(space) |
Pads the result with spaces.
This is the default.
|
0 |
Only left-pads numbers with zeros.
With s specifiers this can
also right-pad with zeros.
|
'(char) |
Pads the result with the character (char).
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Width
Either an integer that says how many characters (minimum)
this conversion should result in, or *.
If * is used, then the width is supplied
as an additional integer value preceding the one formatted
by the specifier.
Precision
A period . optionally followed by
either an integer or *,
whose meaning depends on the specifier:
-
For
e, E,
f and F
specifiers: this is the number of digits to be printed
after the decimal point (by default, this is 6).
-
For
g, G,
h and H
specifiers: this is the maximum number of significant
digits to be printed.
-
For
s specifier: it acts as a cutoff point,
setting a maximum character limit to the string.
Note:
If the period is specified without an explicit value for precision,
0 is assumed. If * is used, the precision is
supplied as an additional integer value preceding the one formatted
by the specifier.
Specifiers
| Specifier |
Description |
% |
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.
|
d |
The argument is treated as an integer and presented
as a (signed) decimal number.
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e |
The argument is treated as scientific notation (e.g. 1.2e+2).
|
E |
Like the e specifier 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).
|
g |
General format.
Let P equal the precision if nonzero, 6 if the precision is omitted,
or 1 if the precision is zero.
Then, if a conversion with style E would have an exponent of X:
If P > X ≥ −4, the conversion is with style f and precision P − (X + 1).
Otherwise, the conversion is with style e and precision P − 1.
|
G |
Like the g specifier but uses
E and f.
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h |
Like the g specifier but uses F.
Available as of PHP 8.0.0.
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H |
Like the g specifier but uses
E and F. Available as of PHP 8.0.0.
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o |
The argument is treated as an integer and presented
as an octal number.
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s |
The argument is treated and presented as a string.
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u |
The argument is treated as an integer and presented
as an unsigned decimal number.
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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).
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Warning
The c type specifier ignores padding and width.
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.
Variables will be co-erced to a suitable type for the specifier:
Type Handling
| Type |
Specifiers |
| string |
s |
| int |
d,
u,
c,
o,
x,
X,
b
|
| float |
e,
E,
f,
F,
g,
G,
h,
H
|
-
values
-
Return Values
Returns a string produced according to the formatting string
format.
Errors/Exceptions
As of PHP 8.0.0, a ValueError is thrown if the number of arguments is zero.
Prior to PHP 8.0.0, a E_WARNING was emitted instead.
As of PHP 8.0.0, a ValueError is thrown if [width] is less than zero or bigger than PHP_INT_MAX.
Prior to PHP 8.0.0, a E_WARNING was emitted instead.
As of PHP 8.0.0, a ValueError is thrown if [precision] is less than zero or bigger than PHP_INT_MAX.
Prior to PHP 8.0.0, a E_WARNING was emitted instead.
As of PHP 8.0.0, a ArgumentCountError is thrown when less arguments are given than required.
Prior to PHP 8.0.0, false was returned and a E_WARNING emitted instead.
Examples
Example #1 Argument swapping
The format string supports argument numbering/swapping.
<?php
$num = 5;
$location = 'tree';
$format = 'There are %d monkeys in the %s';
echo sprintf($format, $num, $location);
?>
The above example will output:
There are 5 monkeys in the tree
However imagine we are creating a format string in a separate file,
commonly because we would like to internationalize it and we rewrite it as:
<?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:
<?php
$format = 'The %2$s contains %1$d monkeys';
echo sprintf($format, $num, $location);
?>
An added benefit is that placeholders can be repeated without adding
more arguments in the code.
<?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 below.
Example #2 Specifying padding character
<?php
echo sprintf("%'.9d\n", 123);
echo sprintf("%'.09d\n", 123);
?>
The above example will output:
Example #3 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
Example #4 sprintf: zero-padded integers
<?php
$isodate = sprintf("%04d-%02d-%02d", $year, $month, $day);
?>
Example #5 sprintf: formatting currency
<?php
$money1 = 68.75;
$money2 = 54.35;
$money = $money1 + $money2;
echo $money;
echo "\n";
$formatted = sprintf("%01.2f", $money);
echo $formatted;
?>
The above example will output:
Example #6 sprintf: scientific notation
<?php
$number = 362525200;
echo sprintf("%.3e", $number);
?>
The above example will output:
See Also
- printf
- fprintf
- vprintf
- vsprintf
- vfprintf
- sscanf
- fscanf
- number_format
- date
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