(PHP 4, PHP 5, PHP 7, PHP 8)
sprintf — 返回格式化字符串
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.
An integer followed by a dollar sign $,
to specify which number argument to treat in the conversion.
| Flag | 说明 |
|---|---|
- |
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). |
An integer that says how many characters (minimum) this conversion should result in.
A period . followed by an integer
who's meaning depends on the specifier:
e, E,
f and F
specifiers: this is the number of digits to be printed
after the decimal point (by default, this is 6).
g, G,
h and H
specifiers: this is the maximum number of significant
digits to be printed.
s specifier: it acts as a cutoff point,
setting a maximum character limit to the string.
注意: If the period is specified without an explicit value for precision, 0 is assumed.
注意: Attempting to use a position specifier greater than
PHP_INT_MAXwill generate warnings.
| Specifier | 说明 |
|---|---|
% |
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. |
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.
|
h |
Like the g specifier but uses F.
Available as of PHP 8.0.0.
|
H |
Like the g specifier but uses
E and F. Available as of PHP 8.0.0.
|
o |
The argument is treated as an integer and presented as an octal number. |
s |
The argument is treated 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). |
The c type specifier ignores padding and width
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 | Specifiers |
|---|---|
| string | s |
| int |
d,
u,
c,
o,
x,
X,
b
|
| float |
e,
E,
f,
F,
g,
G,
h,
H
|
values
返回一个根据格式化字符串 format 生成的字符串。
| 版本 | 说明 |
|---|---|
| 8.0.0 |
此函数失败时不再返回 false 。
|
示例 #1 参数替换
支持按顺序用参数替换格式字符串里的占位符。
<?php
$num = 5;
$location = 'tree';
$format = 'There are %d monkeys in the %s';
echo sprintf($format, $num, $location);
?>
以上例程会输出：
There are 5 monkeys in the tree
假设，我们想把它国际化，在一个单独的文件中创建格式字符串，我们将它重写为：
<?php
$format = 'The %s contains %d monkeys';
echo sprintf($format, $num, $location);
?>
我们现在有一个问题。 格式字符串中占位符的顺序与代码中参数的顺序不匹配。 我们希望保持代码原样，并在格式字符串中简单地指出占位符引用的参数。 我们可以这样写格式化字符串：
<?php
$format = 'The %2$s contains %1$d monkeys';
echo sprintf($format, $num, $location);
?>
另外一个好处是占位符可以重复使用，而无需在代码中添加更多参数。
<?php
$format = 'The %2$s contains %1$d monkeys.
That\'s a nice %2$s full of %1$d monkeys.';
echo sprintf($format, $num, $location);
?>
当使用参数替换时，n$
位置指示符 必须紧跟在百分号（%）之后，在任何其他指示符之前，如下所示。
示例 #2 指定填充字符
<?php
echo sprintf("%'.9d\n", 123);
echo sprintf("%'.09d\n", 123);
?>
以上例程会输出：
......123 000000123
示例 #3 位置说明符与其他说明符
<?php
$format = 'The %2$s contains %1$04d monkeys';
echo sprintf($format, $num, $location);
?>
以上例程会输出：
The tree contains 0005 monkeys
示例 #4 sprintf(): 零填充整数
<?php
$isodate = sprintf("%04d-%02d-%02d", $year, $month, $day);
?>
示例 #5 sprintf(): 货币格式
<?php
$money1 = 68.75;
$money2 = 54.35;
$money = $money1 + $money2;
echo $money;
echo "\n";
$formatted = sprintf("%01.2f", $money);
echo $formatted;
?>
以上例程会输出：
123.1 123.10
示例 #6 sprintf(): 科学记数法
<?php
$number = 362525200;
echo sprintf("%.3e", $number);
?>
以上例程会输出：
3.625e+8