This is what I have tried:
foreach ($multiarr as $arr) {
foreach ($arr as $key=>$val) {
if (next($arr) === false) {
//work on last key
} else {
//work
}
}
}
After taking another look, I thinknext is being used wrong here, but I am not sure what to do about it.
Is it possible to see if I'm on the last iteration of this array?
$lastkey = array_pop(array_keys($arr));
$lastvalue = $arr[$lastkey];
If you want to use it in a loop, just compare $lastkey to $key
You will need to keep a count of iterations and check it against the length of the array you are iterating over. The default Iterator implementation in PHP does not allow you to check whether the next element is valid -- next has a void return and the api only exposes a method to check whether the current position is valid. See here http://php.net/manual/en/class.iterator.php. To implement the functionality you are thinking about you would have to implement your own iterator with a peek() or nextIsValid() method.
Try this:
foreach ($multiarr as $arr) {
$cnt=count($arr);
foreach ($arr as $key=>$val) {
if (!--$cnt) {
//work on last key
} else {
//work
}
}
}
See below url i think it help full to you:-
How to get last key in an array?
How to get last key in an array?
Update:
<?php
$array = array(
array(
'first' => 123,
'second' => 456,
'last' => 789),
array(
'first' => 123,
'second' => 456,
'last_one' => 789),
);
foreach ($array as $arr) {
end($arr); // move the internal pointer to the end of the array
$key = key($arr); // fetches the key of the element pointed to by the internal pointer
var_dump($key);
}
output:
string(4) "last" string(4) "last_one"
This function (in theory, I haven't tested it) will return the last and deepest key in a multidemnsional associative array. Give I a run, I think you'll like it.
function recursiveEndOfArrayFinder($multiarr){
$listofkeys = array_keys($multiarr);
$lastkey = end($listofkeys);
if(is_array($multiarr[$lastkey])){
recursiveEndOfArrayFinder($multiarr[$lastkey]);
}else{
return $lastkey;
}
}
Related
Is there any way that I can remove the successive duplicates from the array below while only keeping the first one?
The array is shown below:
$a=array("1"=>"go","2"=>"stop","3"=>"stop","4"=>"stop","5"=>"stop","6"=>"go","7"=>"go","8"=>"stop");
What I want is to have an array that contains:
$a=array("1"=>"go","2"=>"stop","3"=>"go","7"=>"stop");
Successive duplicates? I don't know about native functions, but this one works. Well almost. Think I understood it wrong. In my function the 7 => "go" is a duplicate of 6 => "go", and 8 => "stop" is the new value...?
function filterSuccessiveDuplicates($array)
{
$result = array();
$lastValue = null;
foreach ($array as $key => $value) {
// Only add non-duplicate successive values
if ($value !== $lastValue) {
$result[$key] = $value;
}
$lastValue = $value;
}
return $result;
}
You can just do something like:
if(current($a) !== $new_val)
$a[] = $new_val;
Assuming you're not manipulating that array in between you can use current() it's more efficient than counting it each time to check the value at count($a)-1
So far, if I have to loop through a multidimensional array, I use a foreach loop for each dimension.
e.g for two dimensions
foreach($array as $key=>$value)
{
foreach($value as $k2=>$v2)
{
echo
}
}
What do I do when I don't know the depth of the array? ie the depth is variable.
The only thing I can think of is to code a whole stack of loops and to break the loop if the next value is not an array.This seems a little silly.
Is there a better way?
Yes, you can use recursion. Here's an example where you output all the elements in an array:
function printAll($a) {
if (!is_array($a)) {
echo $a, ' ';
return;
}
foreach($a as $v) {
printAll($v);
}
}
$array = array('hello',
array('world',
'!',
array('whats'),
'up'),
array('?'));
printAll($array);
What you should always remember when doing recursion is that you need a base case where you won't go any deeper.
I like to check for the base case before continuing the function. That's a common idiom, but is not strictly necessary. You can just as well check in the foreach loop if you should output or do a recursive call, but I often find the code to be harder to maintain that way.
The "distance" between your current input and the base case is called a variant and is an integer. The variant should be strictly decreasing in every recursive call. The variant in the previous example is the depth of $a. If you don't think about the variant you risk ending up with infinite recursions and eventually the script will die due to a stack overflow. It's not uncommon to document exactly what the variant is in a comment before recursive functions.
You can do the below function for loop-through-a-multidimensional-array-without-knowing-its-depth
// recursive function loop through the dimensional array
function loop($array){
//loop each row of array
foreach($array as $key => $value)
{
//if the value is array, it will do the recursive
if(is_array($value) ) $array[$key] = loop($array[$key]);
if(!is_array($value))
{
// you can do your algorithm here
// example:
$array[$key] = (string) $value; // cast value to string data type
}
}
return $array;
}
by using above function, it will go through each of the multi dimensional array, below is the sample array you could pass to loop function :
//array sample to pass to loop() function
$data = [
'invoice' => [
'bill_information' => [
'price' => 200.00,
'quantity' => 5
],
'price_per_quantity' => 50.00
],
'user_id' => 20
];
// then you can pass it like this :
$result = loop($data);
var_dump($result);
//it will convert all the value to string for this example purpose
You can use recursion for this problem:
Here is one example
$array = array(1 => array(1 => "a", 2 => array(1 => "b", 2 => "c", 3 => array(1 => "final value"))));
//print_r($array);
printAllValues($array);
function printAllValues($arr) {
if(!is_array($arr)) {
echo '<br />' . $arr;
return;
}
foreach($arr as $k => $v) {
printAllValues($v);
}
}
It will use recursion to loop through array
It will print like
a
b
c
final value
Simple function inside array_walk_recursive to show the level of nesting and the keys and values:
array_walk_recursive($array, function($v, $k) {
static $l = 0;
echo "Level " . $l++ . ": $k => $v\n";
});
Another one showing use with a reference to get a result:
array_walk_recursive($array, function($v) use(&$result) {
$result[] = $v;
});
Based on previous recursion examples, here is a function that keeps an array of the path of keys a value is under, in case you need to know how you got there:
function recurse($a,$keys=array())
{
if (!is_array($a))
{
echo implode("-", $keys)." => $a <br>";
return;
}
foreach($a as $k=>$v)
{
$newkeys = array_merge($keys,array($k));
recurse($v,$newkeys);
}
}
recurse($array);
How would I iterate through an array (300+ items, imported via simplexml) and pull out every item that has a certain $x->channel->item->title and put that into a different array?
I can't make heads or tails of the haystack needle thing or how to push arrays
Say I have an array (needle) like: array("3332","3300","3493","8380") and I want to match if any of those appear through the big array (haystack). How do I do this?
You have to iterate over your big array, and check for the value of $x->channel->item->title. If it meets your criteria, push it into the new array:
$theArray; // Your 300+ array
$lookFor = array('firstthing', 'second thing', 'third thing');
$newArray = array();
foreach($theArray as $x) {
if ( in_array($x->channel->item->title, $lookFor) ) {
array_push($newArray, $x);
}
}
foreach($yourArray as $key => $value)
{
//do your things with $key and/or $value
}
Modifying from Joseph's loop, you can do:
$theArray; // Your 300+ array
$newArray = array();
$matchArray = array("3332","3300","3493","8380");
foreach($theArray as $x) {
if (in_array($x->channel->item->title, $matchArray)) {
array_push($newArray, $x);
}
}
Check out in_array() at http://php.net/manual/en/function.in-array.php
So here is my code:
<?php
$arr = array(array(2 => 5),
array(3 => 4),
array(7 => 10));
foreach ($arr as $v) {
$k = key($v);
if ($k > 5) {
// unset this element from $arr array
}
}
print_r($arr);
// now I would like to get the array without array(7 => 10) member
As you can see, I start with an array of single key => value arrays, I loop through this array and get a key of the current element (which is a single item array).
I need to unset elements of the array with key higher than 5, how could I do that? I might also need to remove elements with value less than 50 or any other condition. Basically I need to be able to get a key of the current array item which is itself an array with a single item.
foreach($arr as $k => $v) {
if(key($v) > 5) {
unset($arr[$k]);
}
}
It is safe in PHP to remove elements from an array while iterating over it using foreach loop:
foreach ($arr as $key => $value) {
if (key($value) > 5) {
unset($arr[$key]);
}
}
Use key() to get the first key from the sub-array.
foreach($arr as $k => $v) {
if(key($v) > 5) {
unset($arr[$k]);
}
}
It's not really safe to add or delete from a collection while iterating through it. How about adding the elements you want to a second array, then dumping the original?
To unset array element we Used unset() and php function like below:
foreach($array as $key=>$value)
{
if(key($value) > 5)
{
unset($array[$key]);
}
}
I have an array like
$myArray =array
(
"0"=>array("dogs",98),
"1"=>array("cats",56),
"2"=>array("buffaloes",78)
)
How can I get a key by providing a value?
e.g. if i search for "buffaloes" array_search may return "2".
Thanks
$myArray =array
(
"0"=>array("dogs",98),
"1"=>array("cats",56),
"2"=>array("buffaloes",78)
);
function findInArray($term, $array) {
foreach($array as $key => $val) {
if(in_array($term, $val, true)) {
return $key;
}
}
}
echo findInArray('buffaloes', $myArray); // 2
echo findInArray(78, $myArray); // 2
function asearch($key, $myArray) {
for ($i = 0; $i < sizeof($myArray); $i++) {
if ($myArray[$i][0] == $key) {
return $i;
}
}
return -1; # no match
}
Though, you'd probably want to restructure your array to:
$myarray = array(
'dogs' => 98,
'cats' => 56,
'buffaloes' => 78
);
And just do:
$myArray['buffaloes']; # 78
The only way you can do it is to iterate over every item and preform a Linear Search
$i = -1;
foreach ($myArray as $key => $item){
if ( $item[0] == 'buffaloes' ){
$i = $key;
break;
}
}
//$i now holds the key, or -1 if it doesn't exist
As you can see, it is really really inefficient, as if your array has 20,000 items and 'buffaloes' is the last item, you have to make 20,000 comparisons.
In other words, you need to redesign your data structures so that you can look something up using the key, for example a better way may be to rearrange your array so that you have the string you are searching for as the key, for example:
$myArray['buffaloes'] = 76;
Which is much much faster, as it uses a better data structure so that it only has to at most n log n comparisons (where n is the number of items in the array). This is because an array is in fact an ordered map.
Another option, if you know the exact value of the value you are searching for is to use array_search
I never heard of built in function. If you want something more general then above solutions you shold write your own function and use recursion. maybe array_walk_recursive would be helpful
You can loop over each elements of the array, testing if the first element of each entry is equal to "buffaloes".
For instance :
foreach ($myArray as $key => $value) {
if ($value[0] == "buffaloes") {
echo "The key is : $key";
}
}
Will get you :
The key is : 2
Another idea (more funny ?), if you want to whole entry, might be to work with array_filter and a callback function that returns true for the "bufalloes" entry :
function my_func($val) {
return $val[0] == "buffaloes";
}
$element = array_filter($myArray, 'my_func');
var_dump($element);
Will get you :
array
2 =>
array
0 => string 'buffaloes' (length=9)
1 => int 78
And
var_dump(key($element));
Gves you the 2 you wanted.