find in array object php

20.07.202219.07.2022 admin 0 Comments

Using php’s array_search on an array of objects

http://php.net/manual/en/function.array-search.php allows me to find the first array key based on an array value.

Can this be accomplished with a single PHP function if the value is nested in an object in the array values, or must it be manually performed as I show below?

2 Answers 2

Just for fun, if the array is 0 based and sequential keys:

This decodes the JSON into an array. You can decode it to an object after if you need that. As of PHP 7 you can use an array of objects:

There’s no single built-in function that provides for arbitrary comparison. You can, however, roll your own generic array search:

This has the benefit of returning an array of matches to the comparison function, rather than a single key which you later have to lookup. It also has performance O(n), which is ok.

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Источник

in_array

(PHP 4, PHP 5, PHP 7, PHP 8)

in_array — Проверяет, присутствует ли в массиве значение

Описание

Список параметров

Возвращаемые значения

Примеры

Пример #1 Пример использования in_array()

Второго совпадения не будет, потому что in_array() регистрозависима, таким образом, программа выведет:

Пример #2 Пример использования in_array() с параметром strict

Результат выполнения данного примера:

Пример #3 Пример использования in_array() с массивом в качестве параметра needle

Результат выполнения данного примера:

Смотрите также

User Contributed Notes 38 notes

Loose checking returns some crazy, counter-intuitive results when used with certain arrays. It is completely correct behaviour, due to PHP’s leniency on variable types, but in «real-life» is almost useless.

The solution is to use the strict checking option.

// First three make sense, last four do not

If you’re working with very large 2 dimensional arrays (eg 20,000+ elements) it’s much faster to do this.

Remember to only flip it once at the beginning of your code though!

# foo it is found in the array or one of its sub array.

For a case-insensitive in_array(), you can use array_map() to avoid a foreach statement, e.g.:

Determine whether an object field matches needle.

= array( new stdClass (), new stdClass () );
$arr [ 0 ]-> colour = ‘red’ ;
$arr [ 1 ]-> colour = ‘green’ ;
$arr [ 1 ]-> state = ‘enabled’ ;

in_array() may also return NULL if the second argument is NULL and strict types are off.

If the strict mode is on, then this code would end up with the TypeError

In a high-voted example, an array is given that contains, amongst other things, true, false and null, against which various variables are tested using in_array and loose checking.

If you have an array like:
$arr = array(0,1,2,3,4,5);

Add an extra if() to adrian foeder’s comment to make it work properly:

If you found yourself in need of a multidimensional array in_array like function you can use the one below. Works in a fair amount of time

This code will search for a value in a multidimensional array with strings or numbers on keys.

I just struggled for a while with this, although it may be obvious to others.

If you have an array with mixed type content such as:

be sure to use the strict checking when searching for a string in the array, or it will match on the 0 int in that array and give a true for all values of needle that are strings strings.

I found out that in_array will *not* find an associative array within a haystack of associative arrays in strict mode if the keys were not generated in the *same order*:

I had wrongly assumed the order of the items in an associative array were irrelevant, regardless of whether ‘strict’ is TRUE or FALSE: The order is irrelevant *only* if not in strict mode.

I would like to add something to beingmrkenny at gmail dot com comparison post. After debugging a system, i discovered a security issue in our system and his post helped me find the problem.

In my additional testing i found out that not matter what you search for in an array, except for 0 and null, you get true as the result if the array contains true as the value.

Examples as php code :

Such the best practice in our case is to use strict mode. Which was not so obvious.

Kelvin’s case-insensitive in_arrayi is fine if you desire loose typing, but mapping strtolower onto the array will (attempt to) cast all array members to string. If you have an array of mixed types, and you wish to preserve the typing, the following will work:

// Note
// You can’t use wildcards and it does not check variable type
?>

A first idea for a function that checks if a text is in a specific column of an array.
It does not use in_array function because it doesn’t check via columns.
Its a test, could be much better. Do not use it without test.

Beware when using this function to validate user input:

$a = array(‘0’ => ‘Opt 1’, ‘1’ => ‘Opt 2’, ‘2’ => ‘Opt 3’);
$v = ‘sql injection’;
var_dump(in_array($v, array_keys($a)));

This will result : true;

If you need to find if a value in an array is in another array you can use the function:

The top voted notes talked about creating strict comparison function, because in_array is insufficient, because it has very lenient type checking (which is PHP default behaviour).

The thing is, in_array is already sufficient. Because as a good programmer, you should never have an array which contains ; all in one array anyway.

It’s better to fix how you store data and retrieve data from user, rather than fixing in_array() which is not broken.

If you’re creating an array yourself and then using in_array to search it, consider setting the keys of the array and using isset instead since it’s much faster.

Recursive in array using SPL

If array contain at least one true value, in_array() will return true every times if it is not false or null

Be careful to use the strict parameter with truth comparisons of specific strings like «false»:

The above example prints:

False is truthy.
False is not truthy.

This function is for search a needle in a multidimensional haystack:

When using numbers as needle, it gets tricky:

Note this behaviour (3rd statement):

in_array(0, array(42)) = FALSE
in_array(0, array(’42’)) = FALSE
in_array(0, array(‘Foo’)) = TRUE
in_array(‘0’, array(‘Foo’)) = FALSE

Watch out for this:

Yes, it seems that is_array thinks that a random string and 0 are the same thing.
Excuse me, that’s not loose checking, that’s drunken logic.
Or maybe I found a bug?

hope this function may be useful to you, it checks an array recursively (if an array has sub-array-levels) and also the keys, if wanted:

If you have a multidimensional array filled only with Boolean values like me, you need to use ‘strict’, otherwise in_array() will return an unexpected result.

Hope this helps somebody, cause it took me some time to figure this out.

If you search for numbers, in_array will convert any strings in your array to numbers, dropping any letters/characters, forcing a numbers-to-numbers comparison. So if you search for 1234, it will say that ‘1234abcd’ is a match. Example:

Esta función falla con las letras acentuadas y con las eñes. Por tanto, no sirve para los caracteres UTF-8.
El siguiente código falla para na cadena = «María Mañas», no reconoce ni la «í» ni la «ñ»:

// ¿La cadena está vacía?
if (empty ($cadena))
<
$correcto = false;
>
else
<
$nombreOapellido = mb_strtoupper ($cadena, «utf-8»);
$longitudCadena = mb_strlen ($cadena, «utf-8»);

I needed a version of in_array() that supports wildcards in the haystack. Here it is:

$haystack = array( ‘*krapplack.de’ );
$needle = ‘www.krapplack.de’ ;

var_dump(in_array(‘invalid’, array(0,10,20)));
The above code gives true since the ‘invalid’ is getting converted to 0 and checked against the array(0,10,20)

but var_dump(in_array(‘invalid’, array(10,20))); gives ‘false’ since 0 not there in the array

A function to check an array of values within another array.

Second element ‘123’ of needles was found as first element of haystack, so it return TRUE.

If third parameter is not set to Strict then, the needle is found in haystack eventhought the values are not same. the limit behind the decimal seems to be 6 after which, the haystack and needle match no matter what is behind the 6th.

In PHP array function the in_array() function mainly used to check the item are available or not in array.

1. Non-strict validation
2. Strict validation

1. Non-strict validation:
This method to validate array with some negotiation. And it allow two parameters.

Note: the Example 1, we use only two parameter. Because we can’t mention `false` value. Because In default the in_array() take `false` as a boolean value.

In above example,
Example 1 : The `key1` is not value in the array. This is key of the array. So this scenario the in_array accept the search key as a value of the array.
Example 2: The value `577` is not in the value and key of the array. It is some similar to the value `579`. So this is also accepted.

So this reason this type is called non-strict function.

2. Strict validation
This method to validate array without any negotiation. And it have three parameters. If you only mention two parameter the `in_array()` function take as a non-strict validation.

This is return `true` only the search string is match exactly with the array value with case sensitivity.

Источник

PHP in_array object comparing?

Can the in_array function compare objects?

For example, I have an array of objects and I want to add them distinctly to another array. Is it possible to check if an object has already been added like so:

or is there any other way?

8 Answers 8

You can use strict comparison:

The in_array function cannot compare objects.

You should create unique key-value pairs from your objects and only need to compare those keys when inserting a new object into your final array.

Assuming that each object has an unique id property, a possible solution would be:

There’s numerous ways you can do this as you can see. I just thought I would add another one. I don’t know why, but when working with object arrays I like to use the array functions which use callbacks.

If your objects have any sort of identifier, which they should if you want to test them for duplication, the following will work:

I did some tests comparing objects with the in_array function. This is my conclusion:

When you try to find the same instance of an object in an array (like OP), then in_array could work with the strict comparison boolean set.

When you try to find any object of the same class but with a different instance, in_array shows counter-intuitive behavior.

There is a great user comment on PHP.net about the counter-intuitive edge cases.

We know from PHP.net that two objects are only the same in strict comparison ( === ) when they are from the same class + instance. Two objects are already the same in loose comparison ( == ) when they are from the same class.

I wrote some tests with objects to see what happens.

The reason is as follow. If you try to find any object with a certain value, you are forced to use loose comparison (because when the class is not the same, strict comparison always fails). But due to PHP’s variable types, in the last tests these checks are considered true, because the value is considered truthy. Also note that the key on the object is ignored in loose comparison.

Источник

array_search

(PHP 4 >= 4.0.5, PHP 5, PHP 7, PHP 8)

array_search — Осуществляет поиск данного значения в массиве и возвращает ключ первого найденного элемента в случае успешного выполнения

Описание

Список параметров

Если needle является строкой, сравнение происходит с учётом регистра.

Возвращаемые значения

Примеры

Пример #1 Пример использования array_search()

Смотрите также

User Contributed Notes 44 notes

in (PHP 5 >= 5.5.0) you don’t have to write your own function to search through a multi dimensional array

$userdb=Array
(
(0) => Array
(
(uid) => ‘100’,
(name) => ‘Sandra Shush’,
(url) => ‘urlof100’
),

(1) => Array
(
(uid) => ‘5465’,
(name) => ‘Stefanie Mcmohn’,
(pic_square) => ‘urlof100’
),

(2) => Array
(
(uid) => ‘40489’,
(name) => ‘Michael’,
(pic_square) => ‘urlof40489’
)
);

simply u can use this

$key = array_search(40489, array_column($userdb, ‘uid’));

About searcing in multi-dimentional arrays; two notes on «xfoxawy at gmail dot com»;

It perfectly searches through multi-dimentional arrays combined with array_column() (min php 5.5.0) but it may not return the values you’d expect.

Secondly, if your array is big, I would recommend you to first assign a new variable so that it wouldn’t call array_column() for each element it searches. For a better performance, you could do;

It’s what the document stated «may also return a non-Boolean value which evaluates to FALSE.»

the recursive function by tony have a small bug. it failes when a key is 0

here is the corrected version of this helpful function:

If you are using the result of array_search in a condition statement, make sure you use the === operator instead of == to test whether or not it found a match. Otherwise, searching through an array with numeric indicies will result in index 0 always getting evaluated as false/null. This nuance cost me a lot of time and sanity, so I hope this helps someone. In case you don’t know what I’m talking about, here’s an example:

hallo every body This function matches two arrays like
search an array like another or not array_match which can match

for searching case insensitive better this:

About searcing in multi-dimentional arrays;
note on «xfoxawy at gmail dot com» and turabgarip at gmail dot com;

$xx = array_column($array, ‘NAME’, ‘ID’);
will produce an array like :
$xx = [
[ID_val] => NAME_val
[ID_val] => NAME_val
]

$yy = array_search(‘tesxt’, array_column($array, ‘NAME’, ‘ID’));
will output expected ID;

To expand on previous comments, here are some examples of
where using array_search within an IF statement can go
wrong when you want to use the array key thats returned.

Take the following two arrays you wish to search:

I was going to complain bitterly about array_search() using zero-based indexes, but then I realized I should be using in_array() instead.

The essence is this: if you really want to know the location of an element in an array, then use array_search, else if you only want to know whether that element exists, then use in_array()

Be careful when search for indexes from array_keys() if you have a mixed associative array it will return both strings and integers resulting in comparison errors

/* The above prints this, as you can see we have mixed keys
array(3) <
[0]=>
int(0)
[1]=>
string(3) «car»
[2]=>
int(1)
>
*/

hey i have a easy multidimensional array search function

Despite PHP’s amazing assortment of array functions and juggling maneuvers, I found myself needing a way to get the FULL array key mapping to a specific value. This function does that, and returns an array of the appropriate keys to get to said (first) value occurrence.

But again, with the above solution, PHP again falls short on how to dynamically access a specific element’s value within the nested array. For that, I wrote a 2nd function to pull the value that was mapped above.

I needed a way to return the value of a single specific key, thus:

Better solution of multidimensional searching.

FYI, remember that strict mode is something that might save you hours.

one thing to be very aware of is that array_search() will fail if the needle is a string and the array itself contains values that are mixture of numbers and strings. (or even a string that looks like a number)

The problem is that unless you specify «strict» the match is done using == and in that case any string will match a numeric value of zero which is not what you want.

also, php can lookup an index pretty darn fast. for many scenarios, it is practical to maintain multiple arrays, one in which the index of the array is the search key and the normal array that contains the data.

//very fast lookup, this beats any other kind of search

I had an array of arrays and needed to find the key of an element by comparing actual reference.
Beware that even with strict equality (===) php will equate arrays via their elements recursively, not by a simple internal pointer check as with class objects. The === can be slow for massive arrays and also crash if they contain circular references.

This function performs reference sniffing in order to return the key for an element that is exactly a reference of needle.

A simple recursive array_search function :

A variation of previous searches that returns an array of keys that match the given value:

I needed a function, that returns a value by specifying a keymap to the searched value in a multidimensional array and came up with this.

My function get_key_in_array() needed some improvement:

An implementation of a search function that uses a callback, to allow searching for objects of arbitrary complexity:

For instance, if you have an array of objects with an id property, you could search for the object with a specific id like this:

For a more complex example, this function takes an array of key/value pairs and returns the key for the first item in the array that has all those properties with the same values.

The final step is a function that returns the item, rather than its key, or null if no match found:

Источник

efficient way to search object in an array by a property

well, having something like:

what would be the fastest, most efficient way to implement a method like

and would return false if i passed ‘four’ as a param.

9 Answers 9

You can iterate that objects:

Edit:

Faster way is to have an array with keys equals to objects’ ids (if unique);

Then you can build your function as follow:

You can use the function array_search of php like this

It’s an old question but for the canonical reference as it was missing in the pure form:

The false is per the questions requirement to return false. It represents the non-matching value, e.g. you can make it null for example as an alternative suggestion.

This works transparently since PHP 7.0. In case you (still) have an older version, there are user-space implementations of it that can be used as a drop-in replacement.

However array_column also means to copy a whole array. This might not be wanted.

Instead it could be used to index the array and then map over with array_flip :

On the index the search problem might still be the same, the map just offers the index in the original array so there is a reference system.

Keep in mind thought that this might not be necessary as PHP has copy-on-write. So there might be less duplication as intentionally thought. So this is to show some options.

Another option is to go through the whole array and unless the object is already found, check for a match. One way to do this is with array_reduce :

This variant again is with the returning false requirement for no-match.

It is a bit more straight forward with null :

Fully exposing to foreach within a function of its own even has the benefit to directly exit on match:

This is effectively the original answer by hsz, which shows how universally it can be applied.

Источник

Бизнес портал

find in array object php

Using php’s array_search on an array of objects

2 Answers 2