vsprintf

(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)

vsprintf — 返回格式化字符串

说明

vsprintf(string $format, array $values): string

作用与 sprintf() 函数类似，但是接收一个数组参数，而不是一系列可变数量的参数。

参数

format

format 字符串通常由零或多个指令组成：普通字符（不包含 %）——直接复制到结果，转换规范——获取每个参数的结果。

转换规范遵循此原型： %[argnum$][flags][width][.precision]specifier.

Argnum

整数后跟美元符号 $，用于指定转换中要处理的参数数量。

标志
标志 说明
- 在指定字段宽度时左对齐，默认右对齐
+ 正数的加号 +前缀，默认负数的前缀是负号。
(space) 空格填充结果。这是默认设置。
0 仅用 0 进行左侧数字填充。使用 s 标志符可以右侧填充。
'(char) 用字符（char）填充结果。

Width

要么是整数，表示转换结果应该有多少个字符（最少），要么是 *。如果使用 *，那么宽度将作为额外的整数值提供，位于格式化符号之前。

Precision

小数点 .，可选的后跟整数或者 *，其含义取决于格式化符号：

  • e、E、f、F 标志符：小数点后需要打印的位数（默认是 6）。
  • g、G、h、H 标志符：这是要打印的最大有效位数。
  • s 标志符：充当分界点，为字符串设置最大字符限制。

注意: 如果小数点没有明确的精度值，则假设是 0。如果使用 *，则精度将作为额外的整数值提供，位于格式化符号之前。

标志符
标志符 说明
% 字面意思的百分号字符。不需要参数。
b 参数视为整数并以二进制数字呈现。
c 参数视为整数并以 ASCII 字符呈现。
d 参数视为整数并以（有符号）十进制数字呈现。
e 参数当做科学符号处理（例如 1.2e+2）。
E 与 e 标志符相同，但使用大写字母（例如 1.2E+2）。
f 参数当做浮点数处理且作为浮点数呈现（locale aware）。
F 参数当做浮点数处理且作为浮点数呈现（non-locale aware）。
g

通用格式。

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 参数视为整数并以八进制数字来呈现。
s 参数视为字符串来呈现。
u 参数视为整数并以无符号十进制数字呈现。
x 参数视为整数并作为十六进制数字呈现（带小写字母）。
X 参数视为整数并作为十六进制数字呈现（带大写字母）。
警告

c 类型标志符忽略填充和宽度。

警告

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.

变量将会强制转换为适合标志符的类型：

类型处理
类型 标志符
string s
int d, u, c, o, x, X, b
float e, E, f, F, g, G, h, H
values

返回值

根据 format 和数组参数返回处理后的字符串。

错误／异常

从 PHP 8.0.0 开始，如果参数个数为零，将抛出 ValueError。在 PHP 8.0.0 之前，会发出 E_WARNING。

从 PHP 8.0.0 开始，如果 [width] 小于零或大于 PHP_INT_MAX，则会抛出 ValueError。在 PHP 8.0.0 之前，会发出 E_WARNING。

从 PHP 8.0.0 开始，如果 [precision] 小于零或大于 PHP_INT_MAX，则会抛出 ValueError。在 PHP 8.0.0 之前，会发出 E_WARNING。

从 PHP 8.0.0 开始，当传递的参数少于所需的参数时会抛出 ValueError。在 PHP 8.0.0 之前，返回 false 并发出 E_WARNING。

更新日志

版本 说明
8.0.0 此函数失败时不再返回 false。
8.0.0 如果参数个数为零则抛出 ValueError；以前该函数则会发出 E_WARNING。
8.0.0 如果 [width] 小于零或大于 PHP_INT_MAX，则抛出 ValueError；以前该函数则会发出 E_WARNING。
8.0.0 如果 [precision] 小于零或大于 PHP_INT_MAX，则抛出 ValueError；以前该函数则会发出 E_WARNING。
8.0.0 当传递的参数少于所需的参数时抛出 ValueError；以前该函数则会发出 E_WARNING。

示例

示例 #1 vsprintf(): 前导 0 的整数

<?php
print vsprintf("%04d-%02d-%02d", explode('-', '1988-8-1'));
?>

以上示例会输出：

1988-08-01

参见

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用户贡献的备注 10 notes

up
46
spectrumcat
8 years ago
Instead of inventing own functions in case you'd like to use array keys as placeholder names and replace corresponding array values in a string, just use the str_replace:

$string = 'Hello %name!';
$data = array(
'%name' => 'John'
);

$greeting = str_replace(array_keys($data), array_values($data), $string);
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13
Josef Kufner
12 years ago
<?php
/**
* Like vsprintf, but accepts $args keys instead of order index.
* Both numeric and strings matching /[a-zA-Z0-9_-]+/ are allowed.
*
* Example: vskprintf('y = %y$d, x = %x$1.1f', array('x' => 1, 'y' => 2))
* Result: 'y = 2, x = 1.0'
*
* $args also can be object, then it's properties are retrieved
* using get_object_vars().
*
* '%s' without argument name works fine too. Everything vsprintf() can do
* is supported.
*
* @author Josef Kufner <jkufner(at)gmail.com>
*/
function vksprintf($str, $args)
{
if (is_object($args)) {
$args = get_object_vars($args);
}
$map = array_flip(array_keys($args));
$new_str = preg_replace_callback('/(^|[^%])%([a-zA-Z0-9_-]+)\$/',
function($m) use ($map) { return $m[1].'%'.($map[$m[2]] + 1).'$'; },
$str);
return vsprintf($new_str, $args);
}
?>
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4
crash
3 years ago
Note that this function now throws an ValueError* as of PHP 8.0 if there is an error:

$ php -r 'var_dump(vsprintf("%d", []));'
> Fatal error: Uncaught ValueError: The arguments array must contain 1 items, 0 given in Command line code:1

*ValueError is new in PHP 8.0, so if you want to make your code compatible to PHP 7.x you should test that the arguments array has the correct length.
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1
steven at nevvix dot com
6 years ago
<?php
/**
* Return a formatted string like vsprintf() with named placeholders.
*
* When a placeholder doesn't have a matching key in `$args`,
* the placeholder is returned as is to see missing args.
* @param string $format
* @param array $args
* @param string $pattern
* @return string
*/
function p($format, array $args, $pattern="/\{(\w+)\}/") {
return preg_replace_callback($pattern, function ($matches) use ($args) {
return @$args[$matches[1]] ?: $matches[0];
}, $format);
}

$args = ["database"=>"people", "user"=>"staff", "pass"=>"pass123", "host"=>"localhost"];

// With PHP-like placeholders: the variable is embedded in a string "{$database}" but without the dollar sign
$format = <<<SQL
CREATE DATABASE IF NOT EXISTS {database};
GRANT ALL PRIVILEGES ON {database_name}.* TO '{user}'@'{host}';
SET PASSWORD = PASSWORD('{pass}');
SQL;
echo p($format, $args);
/*
Result:

CREATE DATABASE IF NOT EXISTS people;
GRANT ALL PRIVILEGES ON {database_name}.* TO 'staff'@'localhost';
SET PASSWORD = PASSWORD('pass123');

The `{database_name}` placeholder doesn't exist as a matching key in `$args` so it's returned as is.
*/

// With Ruby-like placeholders
$format = <<<SQL
CREATE DATABASE IF NOT EXISTS :database;
GRANT ALL PRIVILEGES ON :database_name.* TO ':user'@':host';
SET PASSWORD = PASSWORD(':pass');
SQL;
echo p($format, $args, "/:(\w+)/");
/*
Result:

CREATE DATABASE IF NOT EXISTS people;
GRANT ALL PRIVILEGES ON :database_name.* TO 'staff'@'localhost';
SET PASSWORD = PASSWORD('pass123');

The `:database_name` placeholder doesn't exist as a matching key in `$args` so it's returned as is.
*/
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4
jon at ardentcreative dot co dot uk
19 years ago
This can be used for quick and dirty internationalization:

<?php
$GLOBALS['strings']['example'] = "There are %d people.";

// Loads a phrase from the translations list in lang/$lang/phrases.php
function t() {
$args = func_get_args();
$nArgs = func_num_args();

$phrase = array_shift($args);
$nArgs--;

include_once("../lang/" . lang() . "/phrases.php");
if (isset($GLOBALS['strings'][$phrase])) {
return vsprintf($GLOBALS['strings'][$phrase], $args);
} else {
return '<span style="color: #ff0000">Untranslated string: ' . $phrase . '</span>';
}
}
?>
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4
Roadster
18 years ago
Please note: The same functionality (sortof) can be attained between version 4.0.4 and 4.1.0 using call_user_func_array.

Example:

call_user_func_array("sprintf", $arg)

First element of $arg is the format. This rescued me in a situation where version 4.1.0 wasn't available.
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3
www dot wesley at gmail dot com
16 years ago
vnsprintf is equal to vsprintf except for associative, signed or floating keys.

vnsprintf supports for example "%assocKey$05d", "%-2$'+10s" and "%3.2$05u", vsprintf doesn't

vnsprintf( '%2$d', $array) [2nd value] is equal to vsprintf( '%2$d', $array) [2nd value]
vnsprintf( '%+2$d', $array) [key = 2] is equal to vnsprintf( '%2.0$d', $array) [key = 2]
vnsprintf( '%+2$d', $array) [key = 2] is different of vsprintf( '%+2$d', $array) [unsupported]

When you use signed or floating keys, vnsprintf searchs for the signed truncated key of the original array

Note¹: vnsprintf does not support for example "%someKeyf" (floating number, key = someKey) or "%+03d" (signed decimal number, key = 3), you should use "%someKey$f" or "%+03$d" respectively.
Note²: "%+03d" (or "%1$+03d") will be interpreted as signed zero-padded decimal number

<?php
function vnsprintf( $format, array $data)
{
preg_match_all( '/ (?<!%) % ( (?: [[:alpha:]_-][[:alnum:]_-]* | ([-+])? [0-9]+ (?(2) (?:\.[0-9]+)? | \.[0-9]+ ) ) ) \$ [-+]? \'? .? -? [0-9]* (\.[0-9]+)? \w/x', $format, $match, PREG_SET_ORDER | PREG_OFFSET_CAPTURE);
$offset = 0;
$keys = array_keys($data);
foreach ( $match as &$value )
{
if ( ( $key = array_search( $value[1][0], $keys) ) !== FALSE || ( is_numeric( $value[1][0]) && ( $key = array_search( (int)$value[1][0], $keys) ) !== FALSE ) ) {
$len = strlen( $value[1][0]);
$format = substr_replace( $format, 1 + $key, $offset + $value[1][1], $len);
$offset -= $len - strlen( $key);
}
}
return vsprintf( $format, $data);
}

$examples = array(
2.8=>'positiveFloat', // key = 2 , 1st value
-3=>'negativeInteger', // key = -3 , 2nd value
'my_name'=>'someString' // key = my_name , 3rd value
);

echo vsprintf( "%%my_name\$s = '%my_name\$s'\n", $examples); // [unsupported]
echo vnsprintf( "%%my_name\$s = '%my_name\$s'\n", $examples); // output : "someString"

echo vsprintf( "%%2.5\$s = '%2.5\$s'\n", $examples); // [unsupported]
echo vnsprintf( "%%2.5\$s = '%2.5\$s'\n", $examples); // output : "positiveFloat"

echo vsprintf( "%%+2.5\$s = '%+2.5\$s'\n", $examples); // [unsupported]
echo vnsprintf( "%%+2.5\$s = '%+2.5\$s'\n", $examples); // output : "positiveFloat"

echo vsprintf( "%%-3.2\$s = '%-3.2\$s'\n", $examples); // [unsupported]
echo vnsprintf( "%%-3.2\$s = '%-3.2\$s'\n", $examples); // output : "negativeInteger"

echo vsprintf( "%%2\$s = '%2\$s'\n", $examples); // output : "negativeInteger"
echo vnsprintf( "%%2\$s = '%2\$s'\n", $examples); // output : [= vsprintf]

echo vsprintf( "%%+2\$s = '%+2\$s'\n", $examples); // [unsupported]
echo vnsprintf( "%%+2\$s = '%+2\$s'\n", $examples); // output : "positiveFloat"

echo vsprintf( "%%-3\$s = '%-3\$s'\n", $examples); // [unsupported]
echo vnsprintf( "%%-3\$s = '%-3\$s'\n", $examples); // output : "negativeInteger"
?>
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2
dee jay simple zero07 at geemail dawt co
12 years ago
Using a heredoc with vprintf:

<?php
$string = <<<THESTRING
I like the state of %1\$s <br />
I picked: %2\$d as a number, <br />
I also picked %2\$d as a number again <br />
%3\$s<br />
THESTRING;

$returnText = vprintf( $string, array('Oregon','7','I Love Oregon') );

echo $returnText;
?>
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1
jed at NOSPAM dot jed dot bz
20 years ago
vsprintf() accepts arrays with any keys, so the array_shift() technique is unnecessary when writing a printf-type function. Any parameters you require are easily unset from the array you retrieve with func_get_args():

<?php

function mysprintf($format) {
$args = func_get_args();
unset($args[0]); /* get rid of "$format" */
return vsprintf($format, $args);
}

/* I use this technique in production code as follows: */
function logf($target, $string) {
$args = func_get_args();
unset($args[0], $args[1]);
fprintf($GLOBALS['config']['logtargets'][$target],
"[%s] %s\n", date('H:i'), wordwrap(vsprintf($string, $args), 75, '\n\r '));
}

/* e.g.:
logf(DEBUG, "Oops! %s", mysql_error());
*/

?>

array_shift() and other costly array operations aren't required, as far as I know. I could be wrong.
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1
ASchmidt at Anamera dot net
7 years ago
It's necessary to clearly how to apply argument swapping when using an array of arguments. One might be tempted to use %0$ to reference $args[0].

In reality, the position specifier is always the array index+1:

$args[0] is referenced by %1$...
$args[1] is referenced by %2$...
etc.

Similarly, the first subpattern of a RegEx match would be found in $matches[1], the second in $match[2], etc. However if the $matches array is used as arguments to vsprint(), then the position specifier is subpattern+1:

preg_match( $pattern, $subject, $matches );
vsprintf( 'Full Match = %1$s, first Subpattern = %2$s, second Subpattern = %3$s', $matches );
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