Check if two arrays are equal key value with same name - php

Question

I have two arrays:
$arr1 = array(
1 => 250,
2 => 325,
3 => 741,
4 => 690
);
$arr2 = array(
1 => 110,
2 => 740,
3 => 1200,
4 => 500
);
I want to check if all $arr2 values are less than $arr1 values
There are now 2 keys [1] + [4] its less than $arr1 keys [1] + [4]
Without a foreach loop, I want to return true or false if any key from $arr2 is less than the same key from $arr1.

Answer 1

Here is one way to do it.
$result = (bool) array_filter(array_map(function($a, $b){
return $b < $a;
}, $arr1, $arr2));
The inner array_map returns true or false based on the comparison of corresponding values of $arr1 and $arr2. Then the outer array_filter reduces the result to only include true values. Casting the result to boolean will yield true if all values in $arr2 are greater than or equal to the corresponding $arr1 values (because array_filter will return an empty array), and false if any of them are less.
Keep in mind that avoiding a foreach loop is not more efficient for something like this. Both the array_map and array_filter functions will iterate the entire array they are given. If you use a foreach instead, you can break out of the loop as soon as you find an element that meets the condition you're looking for, which in this case would be the first iteration of the foreach loop.

Answer 2

Here is an example that does not use foreach() but most of us would use an iterator to work with array elements. You could use for() or while() loops, too.
<?php // demo/temp_samer.php
/**
* Compare array elements
*
* https://stackoverflow.com/questions/45422576/check-if-two-arrays-are-equal-key-value-with-same-name
*/
error_reporting(E_ALL);
echo '<pre>';
$arr1=array('1'=>250,'2'=>325,'3'=>741,'4'=>690);
$arr2=array('1'=>110,'2'=>740,'3'=>1200,'4'=>500);
if ($arr2[1] < $arr1[1]) echo PHP_EOL . "KEY 1 IS LOWER IN THE SECOND ARRAY";
if ($arr2[2] < $arr1[2]) echo PHP_EOL . "KEY 2 IS LOWER IN THE SECOND ARRAY";
if ($arr2[3] < $arr1[3]) echo PHP_EOL . "KEY 3 IS LOWER IN THE SECOND ARRAY";
if ($arr2[4] < $arr1[4]) echo PHP_EOL . "KEY 4 IS LOWER IN THE SECOND ARRAY";

Answer 3

This shows a way of thinking about the problem.
https://iconoun.com/demo/temp_samer.php
<?php // demo/temp_samer.php
/**
* Compare array elements
*
* https://stackoverflow.com/questions/45422576/check-if-two-arrays-are-equal-key-value-with-same-name
*/
error_reporting(E_ALL);
echo '<pre>';
$arr1=array('1'=>250,'2'=>325,'3'=>741,'4'=>690);
$arr2=array('1'=>110,'2'=>740,'3'=>1200,'4'=>500);
foreach ($arr2 as $key => $value)
{
if ($value < $arr1[$key]) echo PHP_EOL . "KEY $key IS LOWER IN THE SECOND ARRAY";
}