PHP function to validate array - php

Question

Is there a function which I could give an array, which would return true if the provided function returned true for all of them?
theFunction(array(1,2,3) , 'is_numeric') //true
theFunction(array(1,"b",3) , 'is_numeric') //false

Answer 1

No, but you can use array_reduce:
array_reduce(array(1,2,3),
function ($a, $v) { return $a && is_numeric($v); }, true);
You can of course build your own higher-order function:
function for_all(array $arr, $func) {
return array_reduce($arr,
function ($a, $v) use ($func) {
return $a && call_user_func($func, $v);
}, true);
}
var_dump(
for_all(array(1,2,3), 'is_numeric')
); //true

Answer 2

array_filter() does the job:
$data = array(1, 2, 3);
if ($data === array_filter($data, 'is_numeric'))
{
// all values of $data are numeric
}

Answer 3

/**
* all in collection?
*
* Passes each element of the collection to the given function. The method
* returns true if the function never returns false or null.
*
* If the function is not given, an implicit
* function ($v) { return ($v !== null && $v !== false) is added
* (that is all() will return true only if none of the collection members are false or null.)
*
* #param array $arr input array
* #param function $lambda takes an element, returns a bool (optional)
* #return boolean
*/
function all($arr, $lambda=null) {
// these differ from PHP's "falsy" values
if (!is_callable($lambda)) {
foreach ($arr as $value)
if ($value === false || $value === null)
return false;
} else {
foreach ($arr as $value)
if (!call_user_func($lambda, $value))
return false;
}
return true;
}
This is lifted from my implementation of Ruby's enum
You can call it like:
var_dump(all($array, 'is_numeric'));
var_dump(all($array, 'is_string'));
var_dump(all($array, function($x) { return $x != 'fun';})); // PHP >= 5.3.0

Answer 4

If you don't mind about efficiency and care more about simplicity you can use the min and array_map without having to create new functions.
(bool)min(array_map('is_numeric', array(1,2,3))); //true
(bool)min(array_map('is_numeric', array(1,"b",3))); //false
Also if you think about the process as finding one that doesn't fit the pattern you can rewrite it a bit cleaner.
!array_filter('is_not_numeric', array(1,2,3)); //true
!array_filter('is_not_numeric', array(1,"b",3)); //true

Answer 5

This is the function to validate value against validation rules or just use callables: names of PHP functions or closures.
/**
* Returns true if $value matches $pattern
*
* #param $value
* #param string $pattern
*
* #return bool
*
* #see https://github.com/ptrofimov/matchmaker - ultra-fresh PHP matching functions
* #author Petr Trofimov <petrofimov#yandex.ru>
*/
function matcher($value, $pattern)
{
$args = [];
if (($p = ltrim($pattern, ':')) != $pattern) foreach (explode(' ', $p) as $name) {
if (substr($name, -1) == ')') {
list($name, $args) = explode('(', $name);
$args = explode(',', rtrim($args, ')'));
}
if (is_callable(rules($name))) {
if (!call_user_func_array(rules($name), array_merge([$value], $args))) {
return false;
}
} elseif (rules($name) !== $value) {
return false;
}
} else {
return $pattern === '' || $value === $pattern;
}
return true;
}
You can use it with prepared set of validation rules, implemented in project matchmaker: https://github.com/ptrofimov/matchmaker