Making a lookup on an array is simple:
$array = array(0 => 'Zero', 1 => 'One', 2 => 'Two');
$text = $array[2]; // $text = 'Two'
But if I don't want the intermediate $array variable, is there any built in way of making a lookup an array literal?
Examples
$text = array(0 => 'Zero', 1 => 'One', 2 => 'Two')[2]; // Syntax error
$text = array_value(2, array(0 => 'Zero', 1 => 'One', 2 => 'Two')); // Unknown command
As of PHP5.5 you can do:
$text = array(0 => 'Zero', 1 => 'One', 2 => 'Two')[2];
For versions lower than 5.5 you'll have to code a function like array_value() on your own as there is no built in function for it. Like this:
function array_value($key, $array) {
if(!array_key_exists($key, $array)) {
throw new Exception('Array has no index ' . $key);
}
return $array[$key];
}
Another solution:
$array = array(0 => 'Zero', 1 => 'One', 2 => 'Two');
$pos = 2;
echo current(array_slice($array, $pos, 1));
Related
I have two arrays:
$a = ['0' => 1, '1' => 2, '2' => 3]
$b = ['0' => 4, '1' => 5, '2' => 6]
I want to create a new array like this:
[
['a' => 1, 'b' => '4'],
['a' => '2', 'b' => '5']
]
I have tried using array_merge and array_merge_recursive, but I wasn't able to get the right results.
$data = array_merge_recursive(array_values($urls), array_values($id));
You have to apply array_map() with custom function:
$newArray = array_map('combine',array_map(null, $a, $b));
function combine($n){
return array_combine(array('a','b'),$n);
}
print_r($newArray);
Output:-https://3v4l.org/okML7
Try this one
$c = array_merge($a,$b)
$d[] = array_reduce($d, 'array_merge', []);
It will merge the two array and reduce and remerge it.
You can use foreach to approach this
$a = ['0' => 1, '1' => 2, '2' => 3];
$b = ['0' => 4, '1' => 5, '2' => 6];
$res = [];
$i = 0;
$total = 2;
foreach($a as $k => $v){
$res[$i]['a'] = $v;
$res[$i]['b'] = $b[$k];
$i++;
if($i == $total) break;
}
The idea is to have an array $ab = ['a','b'] and a array from your both arrays like this $merged_array = [[1,4],[2,5],[3,6]]. Now we can combine array $ab with each element of $merged_array and that will be the result we need.
$first = ['0' => 1, '1' => 2, '2' => 3];
$second = ['0' => 4, '1' => 5, '2' => 6];
$merged_array = [];
for($i=0;$i<count($first);$i++)
{
array_push($merged_array,[$first[$i],$second[$i]]);
}
$final = [];
$ab = ['a','b'];
foreach($merged_array as $arr)
{
array_push($final,array_combine($ab, $arr));
}
print_r($final);
All earlier answers are working too hard. I see excessive iterations, iterated function calls, and counter variables.
Because there are only two arrays and the keys between the two arrays are identical, a simple foreach loop will suffice. Just push associative arrays into the result array.
Code: (Demo)
$a = ['0' => 1, '1' => 2, '2' => 3];
$b = ['0' => 4, '1' => 5, '2' => 6];
$result = [];
foreach ($a as $k => $v) {
$result[] = ['a' => $v, 'b' => $b[$k]];
}
var_export($result);
Output:
array (
0 =>
array (
'a' => 1,
'b' => 4,
),
1 =>
array (
'a' => 2,
'b' => 5,
),
2 =>
array (
'a' => 3,
'b' => 6,
),
)
I have string
$string1 = `a,b,c,d`;
$array1 = explode(',', $string1);
Gives me :
array(
(int) 0 => 'a',
(int) 1 => 'b',
(int) 2 => 'c'
(int) 3 => 'd'
)
But I want it to be like this
array(
'a' => 'a',
'b' => 'b',
'c' => 'c'
'd' => 'd'
)
How do I do that
Use array_combine function
$string = `a,b,c,d`;
$array = explode(',', $string);
var_dump(array_combine($array, $array));
I think you have to create a new array after exploding...
$tmp_arr = explode(',', $string1);
$array1 = array();
foreach ($tmp_arr as $item){
$array1[$item] = $item;
}
I have two arrays, both have the same keys (different values) however array #2 is in a different order. I want to be able to resort the second array so it is in the same order as the first array.
Is there a function that can quickly do this?
I can't think of any off the top of my head, but if the keys are the same across both arrays then why not just loop over the first one and use its key order to create a new array using the the values from the 2nd one?
$arr1 = array(
'a' => '42',
'b' => '551',
'c' => '512',
'd' => 'gge',
) ;
$arr2 = array(
'd' => 'ordered',
'b' => 'is',
'c' => 'now',
'a' => 'this',
) ;
$arr2ordered = array() ;
foreach (array_keys($arr1) as $key) {
$arr2ordered[$key] = $arr2[$key] ;
}
You can use array_replace
$arr1 = [
'x' => '42',
'y' => '551',
'a' => '512',
'b' => 'gge',
];
$arr2 = [
'a' => 'ordered',
'x' => 'this',
'y' => 'is',
'b' => 'now',
];
$arr2 = array_replace($arr1, $arr2);
$arr2 is now
[
'x' => this,
'y' => is,
'a' => ordered,
'b' => now,
]
foreach(array_keys($array1) as $key)
{
$tempArray[$key] = $array2[$key];
}
$array2 = $tempArray;
I am not completely sure if this is what your after. anyways as long as the the array remains the same size, than this should work for you.
$gamey = array ("wow" => "World of Warcraft", "gw2" => "Guild Wars2", "wiz101" => "Wizard 101");
$gamex = array ("gw2" => "best game", "wiz101" => "WTF?", "wow" => "World greatest");
function match_arrayKeys ($x, $y)
{
$keys = array_keys ($x);
$values = array_values ($y);
for ($x = 0; $x < count ($keys); $x++)
{
$newarray [$keys[$x]] = $y[$keys[$x]];
}
return $newarray;
}
print_r (match_arrayKeys ($gamey, $gamex));
Output
[wow] => World greatest
[gw2] => best game
[wiz101] => WTF?
Try this
CODE
$fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple");
ksort($fruits);
foreach ($fruits as $key => $val) {
echo "$key = $val\n";
}
OUTPUT
a = orange
b = banana
c = apple
d = lemon
Check the php manual for ksort()
I have an array like below
$old = array(
'a' => 'blah',
'b' => 'key',
'c' => 'amazing',
'd' => array(
0 => 'want to replace',
1 => 'yes I want to'
)
);
I have another array having keys to replace with key information.
$keyReplaceInfoz = array('a' => 'newA', 'b' => 'newB', 'c' => 'newC', 'd' => 'newD');
I need to replace all keys of array $old with respective values in array $keyReplaceInfo.
Output should be like this
$old = array(
'newA' => 'blah',
'newB' => 'key',
'newC' => 'amazing',
'newD' => array(
0 => 'want to replace',
1 => 'yes I want to'
)
);
I had to do it manually as below. I am expecting better option. can anyone suggest better way to accomplish this?
$new = array();
foreach ($old as $key => $value)
{
$new[$keyReplaceInfoz[$key]] = $value;
}
I know this can be more simpler.
array_combine(array_merge($old, $keyReplaceInfoz), $old)
I think this looks easier than what you posed.
array_combine(
['newKey1', 'newKey2', 'newKey3'],
array_values(['oldKey1' => 1, 'oldKey2' => 2, 'oldKey3' => 3])
);
This should do the trick as long as you have the same number of values and the same order.
IMO using array_combine, array_merge, even array_intersect_key is overkill.
The original code is good enough, and very fast.
Adapting #shawn-k solution, here is more cleaner code using array_walk, it will only replace desired keys, of course you can modify as per your convenience
array_walk($old, function($value,$key)use ($keyReplaceInfoz,&$old){
$newkey = array_key_exists($key,$keyReplaceInfoz)?$keyReplaceInfoz[$key]:false;
if($newkey!==false){$old[$newkey] = $value;unset($old[$key]);
}
});
print_r($old);
I just solved this same problem in my own application, but for my application $keyReplaceInfoz acts like the whitelist- if a key is not found, that whole element is removed from the resulting array, while the matching whitelisted keys get translated to the new values.
I suppose you could apply this same algorithm maybe with less total code by clever usage of array_map (http://php.net/manual/en/function.array-map.php), which perhaps another generous reader will do.
function filterOldToAllowedNew($key_to_test){
return isset($keyReplaceInfoz[$key_to_test])?$keyReplaceInfoz[$key_to_test]:false;
}
$newArray = array();
foreach($old as $key => $value){
$newkey = filterOldToAllowedNew($key);
if($newkey){
$newArray[$newkey] = $value;
}
}
print_r($newArray);
This question is old but since it comes up first on Google I thought I'd add solution.
// Subject
$old = array('foo' => 1, 'baz' => 2, 'bar' => 3));
// Translations
$tr = array('foo'=>'FOO', 'bar'=>'BAR');
// Get result
$new = array_combine(preg_replace(array_map(function($s){return "/^$s$/";},
array_keys($tr)),$tr, array_keys($old)), $old);
// Output
print_r($new);
Result:
Array
(
[FOO] => 1
[baz] => 2
[BAR] => 3
)
This the solution i have implemented for the same subject:
/**
* Replace keys of given array by values of $keys
* $keys format is [$oldKey=>$newKey]
*
* With $filter==true, will remove elements with key not in $keys
*
* #param array $array
* #param array $keys
* #param boolean $filter
*
* #return $array
*/
function array_replace_keys(array $array,array $keys,$filter=false)
{
$newArray=[];
foreach($array as $key=>$value)
{
if(isset($keys[$key]))
{
$newArray[$keys[$key]]=$value;
}
elseif(!$filter)
{
$newArray[$key]=$value;
}
}
return $newArray;
}
This works irrespective of array order & array count. Output order & value will be based on replaceKey.
$replaceKey = array('a' => 'newA', 'b' => 'newB', 'c' => 'newC', 'd' => 'newD', 'e' => 'newE','f'=>'newF');
$array = array(
'a' => 'blah',
'd' => array(
0 => 'want to replace',
1 => 'yes I want to'
),
'noKey'=>'RESIDUAL',
'c' => 'amazing',
'b' => 'key',
);
$filterKey = array_intersect_key($replaceKey,$array);
$filterarray = array_intersect_key(array_merge($filterKey,$array),$filterKey);
$replaced = array_combine($filterKey,$filterarray);
//output
var_export($replaced);
//array ( 'newA' => 'blah', 'newB' => 'key', 'newC' => 'amazing', 'newD' => array ( 0 => 'want to replace', 1 => 'yes I want to' ) )
If you're looking for a recursive solution to use on a multidimensional array, have a look at the below method. It will replace all keys requested, and leave all other keys alone.
/**
* Given an array and a set of `old => new` keys,
* will recursively replace all array keys that
* are old with their corresponding new value.
*
* #param mixed $array
* #param array $old_to_new_keys
*
* #return array
*/
function array_replace_keys($array, array $old_to_new_keys)
{
if(!is_array($array)){
return $array;
}
$temp_array = [];
$ak = array_keys($old_to_new_keys);
$av = array_values($old_to_new_keys);
foreach($array as $key => $value){
if(array_search($key, $ak, true) !== false){
$key = $av[array_search($key, $ak)];
}
if(is_array($value)){
$value = array_replace_keys($value, $old_to_new_keys);
}
$temp_array[$key] = $value;
}
return $temp_array;
}
Using OP's example array:
$old = array(
'a' => 'blah',
'b' => 'key',
'c' => 'amazing',
'd' => array(
0 => 'want to replace',
1 => 'yes I want to'
)
);
$replace = ["a" => "AA", 1 => 11];
var_export(array_replace_keys($old, $replace));
Gives the following output:
array (
'AA' => 'blah',
'b' => 'key',
'c' => 'amazing',
'd' =>
array (
0 => 'want to replace',
11 => 'yes I want to',
),
)
DEMO
Inspired by the following snippet.
This uses #Summoner's example but keeps #Leigh's hint in mind:
$start = microtime();
$array = [ "a" => 1, "b" => 2, "c" => 3 ];
function array_replace_key($array, $oldKey, $newKey) {
$keys = array_keys($array);
$idx = array_search($oldKey, $keys);
array_splice($keys, $idx, 1, $newKey);
return array_combine($keys, array_values($array));
}
print_r(array_replace_key($array, "b", "z"));
<?php
$new = array();
foreach ($old as $key => $value)
{
$new[$keyReplaceInfoz][$key] = $value;
}
?>
Say I have the following code:
$arr = array('id' => $tarr = array('1' => 'Fred', '2' => 'Wilma', 'c' => 'Bam Bam'));
echo '' . implode( ', ', $tarr) . '';
This displays: Fred, Wilma, Bam Bam
but the href shows value Array instead of Fred for Fred, Wilma for Wilma etc
Cheers
You can build an output string (or array as shown here) using a foreach loop:
foreach($tarr as $v){
$out[] = "<a href='?tag=$v'>$v</a>";
}
echo implode(', ', $out)
I think what youy are trying to do is this:
$arr = array('1' => 'Fred', '2' => 'Wilma', 'c' => 'Bam Bam');
echo '';
$tarr is an array, so when it's converted to a string, it prints Array.
Don't use implode here, you should use a for loop to get each value of the array.
What you should do is something like this:
$tarr = array('1' => 'Fred', '2' => 'Wilma', 'c' => 'Bam Bam');
$aTags = array();
foreach($tarr as $v){
$aTags[] = ''.$v.'';
}
echo implode(', ', $aTags);
Also, why do you have $arr here? It's totally useless.
$arr = array('id' => $tarr = array('1' => 'Fred', '2' => 'Wilma', 'c' => 'Bam Bam'));
This is the same as:
$tarr = array('1' => 'Fred', '2' => 'Wilma', 'c' => 'Bam Bam');
$arr = array('id' => $tarr);