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array_reduce (PHP 4 >= 4.0.5, PHP 5) array_reduce --
用回调函数迭代地将数组简化为单一的值
说明mixed array_reduce ( array input, callback function [, int initial])
array_reduce() 将回调函数
function 迭代地作用到
input 数组中的每一个单元中，从而将数组简化为单一的值。如果指定了可选参数
initial，该参数将被当成是数组中的第一个值来处理，或者如果数组为空的话就作为最终返回值。
例子 1. array_reduce() 例子 |
<?php
function rsum($v, $w) {
$v += $w;
return $v;
}
function rmul($v, $w) {
$v *= $w;
return $v;
}
$a = array(1, 2, 3, 4, 5);
$x = array();
$b = array_reduce($a, "rsum");
$c = array_reduce($a, "rmul", 10);
$d = array_reduce($x, "rsum", 1);
?>
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这将使 $b 的值为
15，$c 的值为
1200（= 1*2*3*4*5*10），以及
$d 的值为 1。
参见 array_filter()，array_map()，array_unique()
和 array_count_values()。
php dot net at cuntbubble dot com
18-Jan-2002 12:08
There is an error/misleading item in the documentation
[, int
initial]
int is not constrained to an integer, it can be any data
type (although I've not tested ALL data types)
and $v is the
cumulative part, the current value of the reduction.
and I'll take
the liberty to add another example, as used in my
code
<?php
function reduceToTable($html, $p) {
$html .= "<TR><TD><a
href=\"$p.html\">$p</a></td>\n";
return $html;
}
$list = Array("page1",
"page2", "page3");
$tab = array_reduce($list,
"reduceToTable", "<table>\n");
echo $tab .
"</table>\n";
?>
hmm, getting stuff on one
line sure is tricky, it get's wordwrapped on the char count in html so
> counts as 4 chars not one so by the time you've counted "<
you've used up 8 chars
If it get's through moderation could someone
please make it look ok :)
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array_rand
