str_repeat()

(PHP 4, PHP 5, PHP 7)

重复一个字符串

说明

str_repeat(string $input, int $multiplier) : string

返回$input重复$multiplier次后的结果。

参数

$input

待操作的字符串。

$multiplier

$input被重复的次数。

$multiplier必须大于等于 0。如果$multiplier被设置为 0，函数返回空字符串。

返回值

返回重复后的字符串。

范例

Example #1str_repeat()范例

<?php
echo str_repeat("-=", 10);
?>

以上例程会输出：

-=-=-=-=-=-=-=-=-=-=

参见

• for
• str_pad()使用另一个字符串填充字符串为指定长度
• substr_count()计算字串出现的次数

Here is a simple one liner to repeat a string multiple times with a separator:
<?php
implode($separator, array_fill(0, $multiplier, $input));
?>
Example script:
<?php
// How I like to repeat a string using standard PHP functions
$input = 'bar';
$multiplier = 5;
$separator = ',';
print implode($separator, array_fill(0, $multiplier, $input));
print "\n";
// Say, this comes in handy with count() on an array that we want to use in an
// SQL query such as 'WHERE foo IN (...)'
$args = array('1', '2', '3');
print implode(',', array_fill(0, count($args), '?'));
print "\n";
?>
Example Output:
bar,bar,bar,bar,bar
?,?,?

http://php.net/manual/en/function.str-repeat.php#90555
Damien Bezborodov , yeah but execution time of your solution is 3-5 times worse than str_replace.
<?php
function spam($number) {
  return str_repeat('test', $number);
}
function spam2($number) {
  return implode('', array_fill(0, $number, 'test'));
}
//echo spam(4);
$before = microtime(true);
for ($i = 0; $i < 100000; $i++) {
  spam(10);
}
echo microtime(true) - $before , "\n"; // 0.010297
$before = microtime(true);
for ($i = 0; $i < 100000; $i++) {
  spam2(10);
}
echo microtime(true) - $before; // 0.032104

hi guys , 
i've faced this example :
<?php
$my_head = str_repeat("°~", 35);
echo $my_head;
?>
so , the length should be 35x2 = 70 !!!
if we echo it :
<?php
$my_head = str_repeat("°~", 35);
echo strlen($my_head); // 105
echo mb_strlen($my_head, 'UTF-8'); // 70
?>
be carefull with characters and try to use mb_* package to make sure everything goes well ...

str_repeat does not repeat symbol with code 0 on some (maybe all?) systems (tested on PHP Version 4.3.2 , FreeBSD 4.8-STABLE i386 ).
Use <pre>
while(strlen($str) < $desired) $str .= chr(0);
</pre> to have string filled with zero-symbols.

Here is a shorter version of Kees van Dieren's function below, which is moreover compatible with the syntax of str_repeat:
<?php
function str_repeat_extended($input, $multiplier, $separator='')
{
  return $multiplier==0 ? '' : str_repeat($input.$separator, $multiplier-1).$input;
}
?>