I need to check for the existence of a variable.
Variables are not necessarily created in order 1.2.3. They could be created 2.4.3.1. These are also not created at the same time on the same page. So I am just wanted to check for the existence of the variable.
$_SESSION['rule1']
$_SESSION['rule2']
$_SESSION['rule3']
$_SESSION['rule4']
<?
if(isset($_SESSION['rule'.*wildcard*'])) {
do something
}
?>
I'm not sure how to go about this. The answer probably lies in REGEX but I am horrible with REGEX.
If you don't know need to know which rule* key is in the session array, only if any of them are present, then you could try this:
<?php
function prefixExists(array $assoc_array, $prefix)
{
$length = strlen($prefix);
foreach ($assoc_array as $key => $unused)
{
if (strncmp($key, $prefix, $length) === 0) {
return true;
}
}
return false;
}
Testing as follows:
session_start();
var_dump(prefixExists($_SESSION, 'rule'));
$_SESSION['rule3'] = 'some value from form';
var_dump(prefixExists($_SESSION, 'rule'));
Gives output:
bool(false)
bool(true)
Here is another solution with the use of preg_match:
function arrayHasSimilarKey(array $array, $matchKey)
{
$pattern = '/' . str_replace('*', '.*', $matchKey) . '/i';
foreach ($array as $key => $value) { echo $key.PHP_EOL;
if (preg_match($pattern, $key)) {
return true;
}
}
return false;
}
$testArray = ['abc' => 1, 'test_1' => 1, 'test_2' => 1, 'test2_1' => 1, 'test3_2' => 1];
$tests = [
0 => arrayHasSimilarKey($testArray, 'test*'), // true
1 => arrayHasSimilarKey($testArray, 'test2*_2'), // false
2 => arrayHasSimilarKey($testArray, 'test3*'), // true
3 => arrayHasSimilarKey($testArray, 'test3*_1'), // false
4 => arrayHasSimilarKey($testArray, '*_2') // false
];
var_dump($tests);
In your case, $testArray would be $_SESSION
I am trying to solve this problem to learn logic formulations, but this one's really taken too much of my time already.
Rules are simple, No loops and no built in PHP functions (eg. print_r, is_array.. etc).
This is what I have come up with so far.
function displayArray(array $inputArray, $ctr = 0, $tempArray = array()) {
//check if array is equal to temparray
if($inputArray != $tempArray) {
// check if key is not empty and checks if they are not equal
if($inputArray[$ctr]) {
// set current $tempArray key equal to $inputArray's corresponding key
$tempArray[$ctr] = $inputArray[$ctr];
if($tempArray[$ctr] == $inputArray[$ctr]) {
echo $tempArray[$ctr];]
}
$ctr++;
displayArray($inputArray, $ctr);
}
}
}
This program outputs this:
blackgreen
The problem starts when it reaches the element that is an array
$array = array(
'black',
'green',
array(
'purple',
'orange'
)
);
displayArray($array);
Any tips?
This what the return value is supposed to be: blackgreenpurpleorange
This was fun. I decided to make it work with most data types while I was at it. Just don't throw it any objects or nulls and things should work.
No more # error suppression. Now returns the string instead of echoing it.
I realized too late that isset() is actually a language construct rather than a function, and went with a null termination strategy to determine the end of the arrays.
function concatinateRecursive($array, $i = 0) {
static $s = '';
static $depth = 0;
if ($i == 0) $depth++;
// We reached the end of this array.
if ($array === NULL) {
$depth--;
return true;
}
if ($array === array()) return false; // empty array
if ($array === '') return false; // empty string
if (
$array === (int)$array || // int
$array === (float)$array || // float
$array === true || // true
$array === false || // false
$array === "0" || // "0"
$array == "1" || // "1" "1.0" etc.
(float)$array > 1 || // > "1.0"
(int)$array !== 1 // string
)
{
$s .= "$array";
return false;
}
// Else we've got an array. Or at least something we can treat like one. I hope.
$array[] = NULL; // null terminate the array.
if (!concatinateRecursive($array[$i], 0, $s)) {
$depth--;
return concatinateRecursive($array, ++$i, $s);
}
if ($depth == 1) {
return $s;
}
}
$array = array(
'black',
'green',
array(
'purple',
'orange'
)
);
echo concatinateRecursive($array);
blackgreenpurpleorange
Live demo
What about this? You must check if it is array or not.
function display_array(&$array, $index=0) {
if (count($array)<=$index) return;
if (is_array($array[$index])) {
echo '[ ';
display_array($array[$index]);
echo '] ';
}
else
echo "'" . $array[$index] . "' ";
display_array($array, $index+1);
}
// Try:
// $a = ['black', 'green', ['purple', 'orange'], 'beer', ['purple', ['purple', 'orange']]];
// display_array($a);
// Output:
// 'black' 'green' [ 'purple' 'orange' ] 'beer' [ 'purple' [ 'purple' 'orange' ] ]
try this have to use some inbuilt function like isset and is_array but its a complete working recursive method without using loop.
function displayArray(array $inputArray, $ctr = 0) {
if(isset($inputArray[$ctr]))
{
if(is_array($inputArray[$ctr]))
{
return displayArray($inputArray[$ctr]);
}
else
{
echo $inputArray[$ctr];
}
}
else
{
return;
}
$ctr++;
displayArray($inputArray, $ctr);
}
$array = array(
'black',
'green',
array(
'purple',
'orange'
)
);
displayArray($array);
OUTPUT :
blackgreenpurpleorange
DEMO
complete answer
$myarray = array(
'black',
'green',
array(
'purple',
'orange'
)
);
function printAll($a) {
if (!is_array($a)) {
echo $a, ' ';
return;
}
foreach($a as $k => $value) {
if($k<10){
//printAll($k);
printAll($value);
}
}
}
printAll($myarray);
I have a very basic question about PHP, I could not solve it with other answers in stackoverflow.
I have an array like :
[0] => this one i need 1
[1] => this one i need 2
[2] => not need this one
so, I want to check for every one, if it contains 'this one i need', then put that into another array
So we must have this array at least :
[0] => this one i need 1
[1] => this one i need 2
I tried to do it like this but it returned Empty array :
foreach($one as $value) {
if(in_array("my name",$value)) $ok[] = $value;
}
try this
<?php
$one = array();
$one[0] = "this one i need 1";
$one[1] = "this one i need 2";
$one[2] = "not need this one";
$ok = array();
$find_str = "this one i need";
foreach($one as $value) {
if(strpos($value, $find_str) !==false)
{
$ok[] = $value;
}
}
print_r($ok);
?>
OUTPUT :
Array
(
[0] => this one i need 1
[1] => this one i need 2
)
Demo
UPDATE 2 :
as OP's $value is an array
$ok = array();
$find_str = "this one i need";
foreach($one as $value) {
foreach($value as $val){
if(strpos($val, $find_str) !==false)
{
$ok[] = $value;
}
}
}
print_r($ok);
The built-in array_filter() function is intended precisely for this purpose
$needle = 'XYZ';
$newArray = array_filter(
$originalArray,
function ($value) use ($needle) {
return (strpos($value, $needle) !== false);
}
);
array_filter is the perfect tool to delete unwanted elements based on values
$one[0] = "this one i need 1";
$one[1] = "this one i need 2";
$one[2] = "not need this one";
$wanted_string = 'this one i need';
$array_out = array_filter($one, function($var) use($wanted_string) {
return strpos($var, $wanted_string) !== false;
});
// array(2) { [0]=> string(17) "this one i need 1" [1]=> string(17) "this one i need 2" }
For array with single values like
array(2) {
["blue"]=>
int(0)
["red"]=>
int(1)
}
I use this code
<?php
if (array_key_exists('blue',$array))
{
echo "jo";
}
?>
But what code do I need to use for arrays like this
array(2) {
["yellow blue"]=>
int(0)
["red white"]=>
int(1)
}
to check if blue exists?
My take:
if(preg_grep('/blue/', array_keys($array))) { echo 'found'; }
Or if you want to get them:
$matches = preg_grep('/blue/', array_keys($array));
print_r($matches);
$partialKey = 'blue';
$byPartialKey = function ($key) use ($partialKey) {
$parts = explode(' ', $key);
return in_array($partialKey, $parts);
};
$result = array_filter (array_keys($input), $byPartialKey);
$result now contains all keys, that somehow contains $partialKey.
you can do using regular expression
search='blue';
foreach ($array as $key => $value) {
if (preg_match('~'.$search.'~i',$key)) {
echo "jo";
}
}
The \b in the pattern indicates a word boundary, so only the distinct
word "blue" is matched, and not a word partial like "bluegreen"
search='blue';
foreach ($array as $key => $value) {
if (preg_match('/\b'.$search.'\b/i',$key)) {
echo "jo";
}
}
Reference
I would do it like this:
function subkey_exists($string, $array) {
foreach($array as $key => $value) {
$sub_keys = explode(" ", $key);
if(in_array($string,$sub_keys)) {
return true;
}
}
return false;
}
[edit]
updated to your requirements
Yet another array_filter solution :
<?php
function find_keys_like($key, $array) {
return array_filter(array_keys($array), function($k) use (&$key) {
return strpos($k, $key) > -1;
});
}
function array_has_key_like($key, $array) {
return count(find_keys_like($key, $array)) > 0;
}
//test
$a = array('blue' => 1, 'yellow blue' => 2, 'green' => 3);
print_r(find_keys_like('blue', $a));
echo 'blue exists ? ' . (array_has_key_like('blue', $a) ? 'yes' : 'no') . PHP_EOL;
/** result :
Array
(
[0] => blue
[1] => yellow blue
)
blue exists ? yes
*/
This question already has answers here:
Filter multidimensional array based on partial match of search value
(3 answers)
Native function to filter array by prefix
(6 answers)
Closed 1 year ago.
I have an array and I'd like to search for the string 'green'. So in this case it should return the $arr[2]
$arr = array(0 => 'blue', 1 => 'red', 2 => 'green string', 3 => 'red');
is there any predefined function like in_array() that does the job rather than looping through it and compare each values?
For a partial match you can iterate the array and use a string search function like strpos().
function array_search_partial($arr, $keyword) {
foreach($arr as $index => $string) {
if (strpos($string, $keyword) !== FALSE)
return $index;
}
}
For an exact match, use in_array()
in_array('green', $arr)
You can use preg_grep function of php. It's supported in PHP >= 4.0.5.
$array = array(0 => 'blue', 1 => 'red', 2 => 'green string', 3 => 'red');
$m_array = preg_grep('/^green\s.*/', $array);
$m_array contains matched elements of array.
There are several ways...
$arr = array(0 => 'blue', 1 => 'red', 2 => 'green string', 3 => 'red');
Search the array with a loop:
$results = array();
foreach ($arr as $value) {
if (strpos($value, 'green') !== false) { $results[] = $value; }
}
if( empty($results) ) { echo 'No matches found.'; }
else { echo "'green' was found in: " . implode('; ', $results); }
Use array_filter():
$results = array_filter($arr, function($value) {
return strpos($value, 'green') !== false;
});
In order to use Closures with other arguments there is the use-keyword. So you can abstract it and wrap it into a function:
function find_string_in_array ($arr, $string) {
return array_filter($arr, function($value) use ($string) {
return strpos($value, $string) !== false;
});
}
$results = find_string_in_array ($arr, 'green');
if( empty($results) ) { echo 'No matches found.'; }
else { echo "'green' was found in: " . implode('; ', $results); }
Here's a working example: http://codepad.viper-7.com/xZtnN7
PHP 5.3+
array_walk($arr, function($item, $key) {
if(strpos($item, 'green') !== false) {
echo 'Found in: ' . $item . ', with key: ' . $key;
}
});
for search with like as sql with '%needle%' you can try with
$input = preg_quote('gree', '~'); // don't forget to quote input string!
$data = array(
1 => 'orange',
2 => 'green string',
3 => 'green',
4 => 'red',
5 => 'black'
);
$result = preg_filter('~' . $input . '~', null, $data);
and result is
{
"2": " string",
"3": ""
}
function check($string)
{
foreach($arr as $a) {
if(strpos($a,$string) !== false) {
return true;
}
}
return false;
}
A quick search for a phrase in the entire array might be something like this:
if (preg_match("/search/is", var_export($arr, true))) {
// match
}
function findStr($arr, $str)
{
foreach ($arr as &$s)
{
if(strpos($s, $str) !== false)
return $s;
}
return "";
}
You can change the return value to the corresponding index number with a little modification if you want, but since you said "...return the $arr[2]" I wrote it to return the value instead.
In order to find out if UTF-8 case-insensitive substring is present in array, I found that this method would be much faster than using mb_strtolower or mb_convert_case:
Implode the array into a string: $imploded=implode(" ", $myarray);.
Convert imploded string to lowercase using custom function:
$lowercased_imploded = to_lower_case($imploded);
function to_lower_case($str)
{
$from_array=["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","Ä","Ö","Ü","Õ","Ž","Š"];
$to_array=["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","ä","ö","ü","õ","ž","š"];
foreach($from_array as $key=>$val){$str=str_replace($val, $to_array[$key], $str);}
return $str;
}
Search for match using ordinary strpos: if(strpos($lowercased_imploded, "substring_to_find")!==false){do something}
This is a function for normal or multidimensional arrays.
Case in-sensitive
Works for normal arrays and multidimentional
Works when finding full or partial stings
Here's the code (version 1):
function array_find($needle, array $haystack, $column = null) {
if(is_array($haystack[0]) === true) { // check for multidimentional array
foreach (array_column($haystack, $column) as $key => $value) {
if (strpos(strtolower($value), strtolower($needle)) !== false) {
return $key;
}
}
} else {
foreach ($haystack as $key => $value) { // for normal array
if (strpos(strtolower($value), strtolower($needle)) !== false) {
return $key;
}
}
}
return false;
}
Here is an example:
$multiArray = array(
0 => array(
'name' => 'kevin',
'hobbies' => 'Football / Cricket'),
1 => array(
'name' => 'tom',
'hobbies' => 'tennis'),
2 => array(
'name' => 'alex',
'hobbies' => 'Golf, Softball')
);
$singleArray = array(
0 => 'Tennis',
1 => 'Cricket',
);
echo "key is - ". array_find('cricket', $singleArray); // returns - key is - 1
echo "key is - ". array_find('cricket', $multiArray, 'hobbies'); // returns - key is - 0
For multidimensional arrays only - $column relates to the name of the key inside each array.
If the $needle appeared more than once, I suggest adding onto this to add each key to an array.
Here is an example if you are expecting multiple matches (version 2):
function array_find($needle, array $haystack, $column = null) {
$keyArray = array();
if(is_array($haystack[0]) === true) { // for multidimentional array
foreach (array_column($haystack, $column) as $key => $value) {
if (strpos(strtolower($value), strtolower($needle)) !== false) {
$keyArray[] = $key;
}
}
} else {
foreach ($haystack as $key => $value) { // for normal array
if (strpos(strtolower($value), strtolower($needle)) !== false) {
$keyArray[] = $key;
}
}
}
if(empty($keyArray)) {
return false;
}
if(count($keyArray) == 1) {
return $keyArray[0];
} else {
return $keyArray;
}
}
This returns the key if it has just one match, but if there are multiple matches for the $needle inside any of the $column's then it will return an array of the matching keys.
Hope this helps :)