本文实例讲述了PHP实现数组的笛卡尔积运算。分享给大家供大家参考,具体如下:
数组的笛卡尔积在实际中还是挺有用处的,比如计算商品的规格时就经常用到,下面写一种实现方式,如下代码
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$arr = array (
array (2),
array (6,7),
array ( 'a' , 'b' , 'c' )
);
function dikaer( $arr ){
$arr1 = array ();
$result = array_shift ( $arr );
while ( $arr2 = array_shift ( $arr )){
$arr1 = $result ;
$result = array ();
foreach ( $arr1 as $v ){
foreach ( $arr2 as $v2 ){
if (! is_array ( $v )) $v = array ( $v );
if (! is_array ( $v2 )) $v2 = array ( $v2 );
$result [] = array_merge_recursive ( $v , $v2 );
}
}
}
return $result ;
}
|
以上例子输出的结果如下:
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Array
(
[0] => Array
(
[0] => 2
[1] => 6
[2] => a
)
[1] => Array
(
[0] => 2
[1] => 6
[2] => b
)
[2] => Array
(
[0] => 2
[1] => 6
[2] => c
)
[3] => Array
(
[0] => 2
[1] => 7
[2] => a
)
[4] => Array
(
[0] => 2
[1] => 7
[2] => b
)
[5] => Array
(
[0] => 2
[1] => 7
[2] => c
)
)
|
如果需要输出字符串形式的结果可以把代码改成这样
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function dikaer( $arr ){
$arr1 = array ();
$result = array_shift ( $arr );
while ( $arr2 = array_shift ( $arr )){
$arr1 = $result ;
$result = array ();
foreach ( $arr1 as $v ){
foreach ( $arr2 as $v2 ){
$result [] = $v . ',' . $v2 ;
}
}
}
return $result ;
}
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输出结果如下所示:
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Array
(
[0] => 2,6,a
[1] => 2,6,b
[2] => 2,6,c
[3] => 2,7,a
[4] => 2,7,b
[5] => 2,7,c
)
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希望本文所述对大家PHP程序设计有所帮助。
原文链接:http://blog.csdn.net/chenbalala/article/details/52618665