I have an array like this :
array() {
["AG12345"]=>
array() {
}
["AG12548"]=>
array() {
}
["VP123"]=>
array() {
}
I need to keep only arrays with keys which begin with "VP"
It's possible to do it with one function ?
-
1Possible Duplicate stackoverflow.com/questions/2304570/…CLo– CLo2012-03-12 15:29:44 +00:00Commented Mar 12, 2012 at 15:29
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5 Answers
Yes, just use unset():
foreach ($array as $key=>$value)
{
if(substr($key,0,2)!=="VP")
{
unset($array[$key]);
}
}
4 Comments
Minras
+1, but I'd use
substr() instead of regexp. It is simpler and faster.crunkchitis
why is the "!" in there on line 3?
crunkchitis
@JackManey - I'm new to php so I didn't know "!==" existed, I only knew about "!=". Turns out it was important to what I was working on. Identical vs. equal. Thanks.
From a previous question: How to delete object from array inside foreach loop?
foreach($array as $elementKey => $element) {
if(strpos($elementKey, "VP") == 0){
//delete this particular object from the $array
unset($array[$elementKey]);
}
}
Comments
This works for me:
$prefix = 'VP';
for ($i=0; $i <= count($arr); $i++) {
if (strpos($arr[$i], $prefix) !== 0)
unset($arr[$i]);
}
1 Comment
anubhava
That's fair you are OP after all :) but to me substr function will also need another function call i.e. strlen to get the length of the prefix.
Another alternative (this would be way simpler if it were values instead):
array_intersect_key($arr, array_flip(preg_grep('~^VP~', array_keys($arr))));
Comments
This is only a sample how to do this, you have probably many other ways!
// sample array
$alpha = array("AG12345"=>"AG12345", "VP12548"=>"VP12548");
foreach($alpha as $val)
{
$arr2 = str_split($val, 2);
if ($arr2[0] == "VP")
$new_array = array($arr2[0]=>"your_values");
}
