I have a variety of arrays that will either contain
story & message
or just
story
How would I check to see if an array contains both story and message? array_key_exists() only looks for that single key in the array.
Is there a way to do this?
Here is a solution that's scalable, even if you want to check for a large number of keys:
<?php
// The values in this arrays contains the names of the indexes (keys)
// that should exist in the data array
$required = array('key1', 'key2', 'key3');
$data = array(
'key1' => 10,
'key2' => 20,
'key3' => 30,
'key4' => 40,
);
if (count(array_intersect_key(array_flip($required), $data)) === count($required)) {
// All required keys exist!
}
If you only have 2 keys to check (like in the original question), it's probably easy enough to just call array_key_exists() twice to check if the keys exists.
if (array_key_exists("story", $arr) && array_key_exists("message", $arr)) {
// Both keys exist.
}
However this obviously doesn't scale up well to many keys. In that situation a custom function would help.
function array_keys_exists(array $keys, array $arr) {
return !array_diff_key(array_flip($keys), $arr);
}
Surprisingly array_keys_exist doesn't exist?! In the interim that leaves some space to figure out a single line expression for this common task. I'm thinking of a shell script or another small program.
Note: each of the following solutions use concise […] array declaration syntax available in php 5.4+
array_diff + array_keys
if (0 === count(array_diff(['story', 'message', '…'], array_keys($source)))) {
// all keys found
} else {
// not all
}
(hat tip to Kim Stacks)
This approach is the most brief I've found. array_diff() returns an array of items present in argument 1 not present in argument2. Therefore an empty array indicates all keys were found. In php 5.5 you could simplify 0 === count(…) to be simply empty(…).
array_reduce + unset
if (0 === count(array_reduce(array_keys($source),
function($in, $key){ unset($in[array_search($key, $in)]); return $in; },
['story', 'message', '…'])))
{
// all keys found
} else {
// not all
}
Harder to read, easy to change. array_reduce() uses a callback to iterate over an array to arrive at a value. By feeding the keys we're interested in the $initial value of $in and then removing keys found in source we can expect to end with 0 elements if all keys were found.
The construction is easy to modify since the keys we're interested in fit nicely on the bottom line.
array_filter & in_array
if (2 === count(array_filter(array_keys($source), function($key) {
return in_array($key, ['story', 'message']); }
)))
{
// all keys found
} else {
// not all
}
Simpler to write than the array_reduce solution but slightly tricker to edit. array_filter is also an iterative callback that allows you to create a filtered array by returning true (copy item to new array) or false (don't copy) in the callback. The gotchya is that you must change 2 to the number of items you expect.
This can be made more durable but verge's on preposterous readability:
$find = ['story', 'message'];
if (count($find) === count(array_filter(array_keys($source), function($key) use ($find) { return in_array($key, $find); })))
{
// all keys found
} else {
// not all
}
One more possible solution:
if (!array_diff(['story', 'message'], array_keys($array))) {
// OK: all the keys are in $array
} else {
// FAIL: some keys are not
}
It seems to me, that the easiest method by far would be this:
$required = array('a','b','c','d');
$values = array(
'a' => '1',
'b' => '2'
);
$missing = array_diff_key(array_flip($required), $values);
Prints:
Array(
[c] => 2
[d] => 3
)
This also allows to check which keys are missing exactly. This might be useful for error handling.
The above solutions are clever, but unnecessarily slow. A simple foreach loop over a few keys is much faster.
function array_keys_exist($keys, $array){
foreach($keys as $key){
if(!array_key_exists($key, $array)) {
return false;
}
}
return true;
}
If you have something like this:
$stuff = array();
$stuff[0] = array('story' => 'A story', 'message' => 'in a bottle');
$stuff[1] = array('story' => 'Foo');
You could simply count():
foreach ($stuff as $value) {
if (count($value) == 2) {
// story and message
} else {
// only story
}
}
This only works if you know for sure that you ONLY have these array keys, and nothing else.
Using array_key_exists() only supports checking one key at a time, so you will need to check both seperately:
foreach ($stuff as $value) {
if (array_key_exists('story', $value) && array_key_exists('message', $value) {
// story and message
} else {
// either one or both keys missing
}
}
array_key_exists() returns true if the key is present in the array, but it is a real function and a lot to type. The language construct isset() will almost do the same, except if the tested value is NULL:
foreach ($stuff as $value) {
if (isset($value['story']) && isset($value['message']) {
// story and message
} else {
// either one or both keys missing
}
}
Additionally isset allows to check multiple variables at once:
foreach ($stuff as $value) {
if (isset($value['story'], $value['message']) {
// story and message
} else {
// either one or both keys missing
}
}
Now, to optimize the test for stuff that is set, you'd better use this "if":
foreach ($stuff as $value) {
if (isset($value['story']) {
if (isset($value['message']) {
// story and message
} else {
// only story
}
} else {
// No story - but message not checked
}
}
What about this:
isset($arr['key1'], $arr['key2'])
only return true if both are not null
if is null, key is not in array
I use something like this quite often
$wantedKeys = ['story', 'message'];
$hasWantedKeys = count(array_intersect(array_keys($source), $wantedKeys)) > 0
or to find the values for the wanted keys
$wantedValues = array_intersect_key($source, array_fill_keys($wantedKeys, 1))
try this
$required=['a','b'];$data=['a'=>1,'b'=>2];
if(count(array_intersect($required,array_keys($data))>0){
//a key or all keys in required exist in data
}else{
//no keys found
}
This is the function I wrote for myself to use within a class.
<?php
/**
* Check the keys of an array against a list of values. Returns true if all values in the list
is not in the array as a key. Returns false otherwise.
*
* #param $array Associative array with keys and values
* #param $mustHaveKeys Array whose values contain the keys that MUST exist in $array
* #param &$missingKeys Array. Pass by reference. An array of the missing keys in $array as string values.
* #return Boolean. Return true only if all the values in $mustHaveKeys appear in $array as keys.
*/
function checkIfKeysExist($array, $mustHaveKeys, &$missingKeys = array()) {
// extract the keys of $array as an array
$keys = array_keys($array);
// ensure the keys we look for are unique
$mustHaveKeys = array_unique($mustHaveKeys);
// $missingKeys = $mustHaveKeys - $keys
// we expect $missingKeys to be empty if all goes well
$missingKeys = array_diff($mustHaveKeys, $keys);
return empty($missingKeys);
}
$arrayHasStoryAsKey = array('story' => 'some value', 'some other key' => 'some other value');
$arrayHasMessageAsKey = array('message' => 'some value', 'some other key' => 'some other value');
$arrayHasStoryMessageAsKey = array('story' => 'some value', 'message' => 'some value','some other key' => 'some other value');
$arrayHasNone = array('xxx' => 'some value', 'some other key' => 'some other value');
$keys = array('story', 'message');
if (checkIfKeysExist($arrayHasStoryAsKey, $keys)) { // return false
echo "arrayHasStoryAsKey has all the keys<br />";
} else {
echo "arrayHasStoryAsKey does NOT have all the keys<br />";
}
if (checkIfKeysExist($arrayHasMessageAsKey, $keys)) { // return false
echo "arrayHasMessageAsKey has all the keys<br />";
} else {
echo "arrayHasMessageAsKey does NOT have all the keys<br />";
}
if (checkIfKeysExist($arrayHasStoryMessageAsKey, $keys)) { // return false
echo "arrayHasStoryMessageAsKey has all the keys<br />";
} else {
echo "arrayHasStoryMessageAsKey does NOT have all the keys<br />";
}
if (checkIfKeysExist($arrayHasNone, $keys)) { // return false
echo "arrayHasNone has all the keys<br />";
} else {
echo "arrayHasNone does NOT have all the keys<br />";
}
I am assuming you need to check for multiple keys ALL EXIST in an array. If you are looking for a match of at least one key, let me know so I can provide another function.
Codepad here http://codepad.viper-7.com/AKVPCH
Hope this helps:
function array_keys_exist($searchForKeys = array(), $inArray = array()) {
$inArrayKeys = array_keys($inArray);
return count(array_intersect($searchForKeys, $inArrayKeys)) == count($searchForKeys);
}
This is old and will probably get buried, but this is my attempt.
I had an issue similar to #Ryan. In some cases, I needed to only check if at least 1 key was in an array, and in some cases, all needed to be present.
So I wrote this function:
/**
* A key check of an array of keys
* #param array $keys_to_check An array of keys to check
* #param array $array_to_check The array to check against
* #param bool $strict Checks that all $keys_to_check are in $array_to_check | Default: false
* #return bool
*/
function array_keys_exist(array $keys_to_check, array $array_to_check, $strict = false) {
// Results to pass back //
$results = false;
// If all keys are expected //
if ($strict) {
// Strict check //
// Keys to check count //
$ktc = count($keys_to_check);
// Array to check count //
$atc = count(array_intersect($keys_to_check, array_keys($array_to_check)));
// Compare all //
if ($ktc === $atc) {
$results = true;
}
} else {
// Loose check - to see if some keys exist //
// Loop through all keys to check //
foreach ($keys_to_check as $ktc) {
// Check if key exists in array to check //
if (array_key_exists($ktc, $array_to_check)) {
$results = true;
// We found at least one, break loop //
break;
}
}
}
return $results;
}
This was a lot easier than having to write multiple || and && blocks.
$colsRequired = ["apple", "orange", "banana", "grapes"];
$data = ["apple"=>"some text", "orange"=>"some text"];
$presentInBoth = array_intersect($colsRequired,array_keys($data));
if( count($presentInBoth) != count($colsRequired))
echo "Missing keys :" . join(",",array_diff($colsRequired,$presentInBoth));
else
echo "All Required cols are present";
Does this not work?
array_key_exists('story', $myarray) && array_key_exists('message', $myarray)
<?php
function check_keys_exists($keys_str = "", $arr = array()){
$return = false;
if($keys_str != "" and !empty($arr)){
$keys = explode(',', $keys_str);
if(!empty($keys)){
foreach($keys as $key){
$return = array_key_exists($key, $arr);
if($return == false){
break;
}
}
}
}
return $return;
}
//run demo
$key = 'a,b,c';
$array = array('a'=>'aaaa','b'=>'ccc','c'=>'eeeee');
var_dump( check_keys_exists($key, $array));
I am not sure, if it is bad idea but I use very simple foreach loop to check multiple array key.
// get post attachment source url
$image = wp_get_attachment_image_src(get_post_thumbnail_id($post_id), 'single-post-thumbnail');
// read exif data
$tech_info = exif_read_data($image[0]);
// set require keys
$keys = array('Make', 'Model');
// run loop to add post metas foreach key
foreach ($keys as $key => $value)
{
if (array_key_exists($value, $tech_info))
{
// add/update post meta
update_post_meta($post_id, MPC_PREFIX . $value, $tech_info[$value]);
}
}
$myArray = array('key1' => '', 'key2' => '');
$keys = array('key1', 'key2', 'key3');
$keyExists = count(array_intersect($keys, array_keys($myArray)));
Will return true, because there are keys from $keys array in $myArray
Something as this could be used
//Say given this array
$array_in_use2 = ['hay' => 'come', 'message' => 'no', 'story' => 'yes'];
//This gives either true or false if story and message is there
count(array_intersect(['story', 'message'], array_keys($array_in_use2))) === 2;
Note the check against 2, if the values you want to search is different you can change.
This solution may not be efficient, but it works!
Updates
In one fat function:
/**
* Like php array_key_exists, this instead search if (one or more) keys exists in the array
* #param array $needles - keys to look for in the array
* #param array $haystack - the <b>Associative</b> array to search
* #param bool $all - [Optional] if false then checks if some keys are found
* #return bool true if the needles are found else false. <br>
* Note: if hastack is multidimentional only the first layer is checked<br>,
* the needles should <b>not be<b> an associative array else it returns false<br>
* The array to search must be associative array too else false may be returned
*/
function array_keys_exists($needles, $haystack, $all = true)
{
$size = count($needles);
if($all) return count(array_intersect($needles, array_keys($haystack))) === $size;
return !empty(array_intersect($needles, array_keys($haystack)));
}
So for example with this:
$array_in_use2 = ['hay' => 'come', 'message' => 'no', 'story' => 'yes'];
//One of them exists --> true
$one_or_more_exists = array_keys_exists(['story', 'message'], $array_in_use2, false);
//all of them exists --> true
$all_exists = array_keys_exists(['story', 'message'], $array_in_use2);
Hope this helps :)
I usually use a function to validate my post and it is an answer for this question too so let me post it.
to call my function I will use the 2 array like this
validatePost(['username', 'password', 'any other field'], $_POST))
then my function will look like this
function validatePost($requiredFields, $post)
{
$validation = [];
foreach($requiredFields as $required => $key)
{
if(!array_key_exists($key, $post))
{
$validation['required'][] = $key;
}
}
return $validation;
}
this will output this
"required": [
"username",
"password",
"any other field"
]
so what this function does is validate and return all the missing fields of the post request.
// sample data
$requiredKeys = ['key1', 'key2', 'key3'];
$arrayToValidate = ['key1' => 1, 'key2' => 2, 'key3' => 3];
function keysExist(array $requiredKeys, array $arrayToValidate) {
if ($requiredKeys === array_keys($arrayToValidate)) {
return true;
}
return false;
}
I have a question, how do I put a condition for a function that returns true or false, if I am sure that the array is empty, but isset() passed it.
$arr = array();
if (isset($arr)) {
return true;
} else {
return false;
}
In this form returns bool(true) and var_dump shows array (0) {}.
If it's an array, you can just use if or just the logical expression. An empty array evaluates to FALSE, any other array to TRUE (Demo):
$arr = array();
echo "The array is ", $arr ? 'full' : 'empty', ".\n";
Sometimes it is suggested instead of just if'ing the array variable like:
if (!$array) {
// empty
}
to write out:
if (empty($array)) {
// empty
}
for readability reasons. Compare empty(php) language construct.
The PHP manually nicely lists what is false and not.
Use PHP's empty() function. It returns true if there are no elements in the array.
http://php.net/manual/en/function.empty.php
Use empty() to check for empty arrays.
if (empty($arr)) {
// it's empty
} else {
// it's not empty
}
You can also check to see how many elements are in the array via the count function:
$arr = array();
if (count($arr) == 0) {
echo "The array is empty!\n";
} else {
echo "The array is not empty! It has " . count($arr) . " elements!\n";
}
use the empty property as
if (!empty($arr)) {
//do what u want if its not empty
} else {
//do what if its empty
}
I have an array
$data = array( 'a'=>'0', 'b'=>'0', 'c'=>'0', 'd'=>'0' );
I want to check if all array values are zero.
if( all array values are '0' ) {
echo "Got it";
} else {
echo "No";
}
Thanks
I suppose you could use array_filter() to get an array of all items that are non-zero ; and use empty() on that resulting array, to determine if it's empty or not.
For example, with your example array :
$data = array(
'a'=>'0',
'b'=>'0',
'c'=>'0',
'd'=>'0' );
Using the following portion of code :
$tmp = array_filter($data);
var_dump($tmp);
Would show you an empty array, containing no non-zero element :
array(0) {
}
And using something like this :
if (empty($tmp)) {
echo "All zeros!";
}
Would get you the following output :
All zeros!
On the other hand, with the following array :
$data = array(
'a'=>'0',
'b'=>'1',
'c'=>'0',
'd'=>'0' );
The $tmp array would contain :
array(1) {
["b"]=>
string(1) "1"
}
And, as such, would not be empty.
Note that not passing a callback as second parameter to array_filter() will work because (quoting) :
If no callback is supplied, all entries of input equal to FALSE (see
converting to boolean) will be removed.
How about:
// ditch the last argument to array_keys if you don't need strict equality
$allZeroes = count( $data ) == count( array_keys( $data, '0', true ) );
Use this:
$all_zero = true;
foreach($data as $value)
if($value != '0')
{
$all_zero = false;
break;
}
if($all_zero)
echo "Got it";
else
echo "No";
This is much faster (run time) than using array_filter as suggested in other answer.
you can loop the array and exit on the first non-zero value (loops until non-zero, so pretty fast, when a non-zero value is at the beginning of the array):
function allZeroes($arr) {
foreach($arr as $v) { if($v != 0) return false; }
return true;
}
or, use array_sum (loops complete array once):
function allZeroes($arr) {
return array_sum($arr) == 0;
}
#fireeyedboy had a very good point about summing: if negative values are involved, the result may very well be zero, even though the array consists of non-zero values
Another way:
if(array_fill(0,count($data),'0') === array_values($data)){
echo "All zeros";
}
Another quick solution might be:
if (intval(emplode('',$array))) {
// at least one non zero array item found
} else {
// all zeros
}
if (!array_filter($data)) {
// empty (all values are 0, NULL or FALSE)
}
else {
// not empty
}
I'm a bit late to the party, but how about this:
$testdata = array_flip($data);
if(count($testdata) == 1 and !empty($testdata[0])){
// must be all zeros
}
A similar trick uses array_unique().
You can use this function
function all_zeros($array){//true if all elements are zeros
$flag = true;
foreach($array as $a){
if($a != 0)
$flag = false;
}
return $flag;
}
You can use this one-liner: (Demo)
var_export(!(int)implode($array));
$array = [0, 0, 0, 0]; returns true
$array = [0, 0, 1, 0]; returns false
This is likely to perform very well because there is only one function call.
My solution uses no glue when imploding, then explicitly casts the generated string as an integer, then uses negation to evaluate 0 as true and non-zero as false. (Ordinarily, 0 evaluates as false and all other values evaluate to true.)
...but if I was doing this for work, I'd probably just use !array_filter($array)
I have the following PHP code:
$required_fields = array ('menu_name','visible','position');
foreach($required_fields as $fieldname)
{
if (!isset($_POST[$fieldname]) || empty($_POST[$fieldname]) )
{
$errors [] = $fieldname;
}
}
menu_name, visible and position are variables that are received through the post method.
When the value of visible is zero, it creates an entry into the error array.
What is the best way to detect if a variable is empty when 0 is considered "not empty"?
From PHP's manual:
empty() returns FALSE if var has a
non-empty and non-zero value.
Do something like this:
if ( !IsSet ( $_POST['field'] ) || Trim ( $_POST['field'] ) == '' )
this will ensure that the field is set and that it does not contain a empty string
In essence: it is the empty() that is causing your problems not IsSet()
Since user data is sloppy, I use a custom function that treats empty spaces as non data. It sounds like this will do exactly what you want. This function will consider "0" to be valid (aka non-empty) data.
function isNullOrEmpty( $arg )
{
if ( !is_array( $arg ) )
{
$arg = array( $arg );
}
foreach ( $arg as $key => $value )
{
$value = trim($value);
if( $value == "" || $value == null )
{
return true;
}
}
return false;
}
Please note it supports arrays too but requires that each value in the array contains data, which can be useful as you can just do something like this:
$required = array( $_POST['name'], $_POST['age'], $_POST['weight'] );
if ( isNullOrEmpty($required) )
{
// required data is missing
}
PS: keep in mind this function will fire off PHP warnings if the value isn't set and there's no easy way around that, but you should NOT have warnings enabled in production anyways.
If you want to assure an array key is present you can use array_key_exists() instead of empty()
The check will become a concatenation of is_array() and array_key_exists(), being paranoid of course
Can't you just add another line with something like:
if (!isset($_POST[$fieldname]) || empty($_POST[$fieldname]) )
{
if ($fieldname != 'visible' || $_POST[$fieldname] != 0)
{
$errors [] = $fieldname;
}
}
Is it possible to use array_map() to test values of an array? I want to make sure that all elements of an array are numeric.
I've tried both
$arrays = array(
array(0,1,2,3 )
, array ( 0,1, "a", 5 )
);
foreach ( $arrays as $arr ) {
if ( array_map("is_numeric", $arr) === FALSE ) {
echo "FALSE\n";
} else {
echo "TRUE\n";
}
}
and
$arrays = array(
array(0,1,2,3 )
, array ( 0,1, "a", 5 )
);
foreach ( $arrays as $arr ) {
if ( ( array_map("is_numeric", $arr) ) === FALSE ) {
echo "FALSE\n";
} else {
echo "TRUE\n";
}
}
And for both I get
TRUE
TRUE
Can this be done? If so, what am I doing wrong?
Note: I am aware that I can get my desired functionality from a foreach loop.
array_map returns an array. So it will always be considered 'true'. Now, if you array_search for FALSE, you might be able to get the desire effects.
From the PHP.net Page
array_map() returns an array containing all the elements of
arr1 after applying the callback function to each one.
This means that currently you have an array that contains true or false for each element. You would need to use array_search(false,$array) to find out if there are any false values.
I'm usually a big advocate of array_map(), array_filter(), etc., but in this case foreach() is going to be the best choice. The reason is that with array_map() and others it will go through the entire array no matter what. But for your purposes you only need to go through the array until you run into a value for which is_numeric() returns false, and as far as I know there's no way in PHP to break out of those methods.
In other words, if you have 1,000 items in your array and the 5th one isn't numeric, using array_map() will still check the remaining 995 values even though you already know the array doesn't pass your test. But if you use a foreach() instead and have it break on is_numeric() == false, then you'll only need to check those first five elements.
You could use filter, but it ends up with a horrible bit of code
$isAllNumeric = count(array_filter($arr, "is_numeric")) === count($arr)
Using a custom function makes it a bit better, but still not perfect
$isAllNumeric = count(array_filter($arr, function($x){return !is_numeric($x);})) === 0
But if you were using custom functions array_reduce would work, but it still has some failings.
$isAllNumeric = array_reduce($arr,
function($x, $y){ return $x && is_numeric($y); },
true);
The failings are that it won't break when it has found what it wants, so the functional suggestions above are not very efficient. You would need to write a function like this:
function array_find(array $array, $callback){
foreach ($array as $x){ //using iteration as PHP fails at recursion
if ( call_user_func($callback, array($x)) ){
return $x;
}
}
return false;
}
And use it like so
$isAllNumeric = array_find($arr, function($x){return !is_numeric($x);})) !== false;
i have two tiny but extremely useful functions in my "standard library"
function any($ary, $func) {
foreach($ary as $val)
if(call_user_func($func, $val)) return true;
return false;
}
function all($ary, $func) {
foreach($ary as $val)
if(!call_user_func($func, $val)) return false;
return true;
}
in your example
foreach ( $arrays as $arr )
echo all($arr, 'is_numeric') ? "ok" : "not ok";
A more elegant approach IMHO:
foreach ($arrays as $array)
{
if (array_product(array_map('is_numeric', $array)) == true)
{
echo "TRUE\n";
}
else
{
echo "FALSE\n";
}
}
This will return true if all the values are numeric and false if any of the values is not numeric.