Looping an array through a second array
Looking to loop through an array of URLs and inject each keyword from a second array into each URL but can't get to grips with the understanding of arrays. Eg:
$key = array("Keyword+1", "Keyword+2", "Keyword+3"),
$url =array("google.co.uk/#hl=en&q=", "bing.com/search?q=","uk.search.yahoo.com/search?vc=&p="),
I'd like the above to output:
google.co.uk/#hl=en&q=Keyword+1
goog开发者_运维技巧le.co.uk/#hl=en&q=Keyword+2 google.co.uk/#hl=en&q=Keyword+3 bing.com/search?q=Keyword+1 bing.com/search?q=Keyword+2 bing.com/search?q=Keyword+3 uk.search.yahoo.com/search?vc=&p=Keyword+1 uk.search.yahoo.com/search?vc=&p=Keyword+2 uk.search.yahoo.com/search?vc=&p=Keyword+3
Is there an efficient way to achieve this? :)
foreach($url as $currenturl)
{
foreach($key as $currentkey)
{
echo $currenturl . $currentkey . '\n';
}
}
try this
Here is how you can do that:
$keys = array("Keyword+1", "Keyword+2", "Keyword+3");
$urls =array("google.co.uk/#hl=en&q=", "bing.com/search?q=","uk.search.yahoo.com/search?vc=&p=");
$my_array = array();
foreach($urls as $url)
{
foreach($keys as $key)
{
$my_array[] = $url . $key;
}
}
print_r($my_array);
Result:
Array
(
[0] => google.co.uk/#hl=en&q=Keyword+1
[1] => google.co.uk/#hl=en&q=Keyword+2
[2] => google.co.uk/#hl=en&q=Keyword+3
[3] => bing.com/search?q=Keyword+1
[4] => bing.com/search?q=Keyword+2
[5] => bing.com/search?q=Keyword+3
[6] => uk.search.yahoo.com/search?vc=&p=Keyword+1
[7] => uk.search.yahoo.com/search?vc=&p=Keyword+2
[8] => uk.search.yahoo.com/search?vc=&p=Keyword+3
)
You first want to loop over the $url
array, then for each item in the $url
array, you also want to loop over all the keys in the $key
array and append them to the item you picked from $url
,
foreach ($url as $u)
{
foreach ($key as $k)
{
echo $u.$k."\n";
}
}
What you're describing is a generalization of the outer product.
It would be more interesting to define a higher order function for this:
/**
* A generalization of the outer product, forming all the possible
* combinations of the elements of the two arrays and feeding them
* to $f.
* The keys are disregarded
**/
function array_outer($f, array $array1, array $array2) {
$res = array();
foreach ($array1 as $e1) {
$cur = array();
foreach ($array2 as $e2) {
$cur[] = $f($e1, $e2);
}
$res[] = $cur;
}
return $res;
}
$f = function ($a,$b) { return $a.$b; };
print_r(array_outer($f, array("a","b","c"), array("1", "2", "3")));
gives:
Array ( [0] => Array ( [0] => a1 [1] => a2 [2] => a3 ) [1] => Array ( [0] => b1 [1] => b2 [2] => b3 ) [2] => Array ( [0] => c1 [1] => c2 [2] => c3 ) )
See Mathematica's Outer
.
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