maximum value in php array for each key value

Question

I want to find out the maximum value of the each key in the array

$arr1= array(
    0=>array(1,2,3),
    1=>array(2,4,6),
    2=>array(25,4,5));
}

I want to find the maximum value for each value for the corresponding key The final output shuld be

$max_array = array(25,4,6);

with the below code i get error max(): When only one parameter is given, it must be an array in

foreach ($res_arr as $k=>$subArray) {
    foreach ($subArray as $id=>$value) {
        $spanmaxArray[$id] = max($value);
    }
}

that is corrected.comparing the [0],[1][2] the first element 1,2,25.The max valus is 25,same way for other elements also.the return value should be also an array. — mark rammmy
– mark rammmy, Commented Feb 4, 2014 at 14:05
@MarioJohnathan Ah I see, array_column() might be handy (PHP 5.5+). demo — HamZa
– HamZa, Commented Feb 4, 2014 at 14:17

Mario · Accepted Answer · 2014-02-04 14:15:33Z

4

First, rotate array to makes columns as lines

$arr1= array(
    0=>array(1,2,3),
    1=>array(2,4,6),
    2=>array(25,4,5)
);

$arr2 = array();

foreach($arr1 as $subArray) {
    foreach($subArray as $k=>$v) {
        $arr2[$k][] = $v;
    }
}

Then, use array_map as @HamZa did

$max_array  = array_map('max', $arr2);
print_r($max_array);

answered Feb 4, 2014 at 14:15

Mario

1,7161 gold badge23 silver badges30 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

rccoros Over a year ago

Spot on answer. Works well!

OfirH · Accepted Answer · 2014-02-04 14:08:02Z

2

foreach ($res_arr as $k=>$subArray){
        $max = 0;
        foreach ($subArray as $id=>$value){
            if ($value>$max){
                $max = $value;
            }
        }
        $spanmaxArray[$k] = $max;
}

Try this.

answered Feb 4, 2014 at 14:08

OfirH

6572 gold badges8 silver badges19 bronze badges

Comments

Digital Chris · Accepted Answer · 2014-02-04 14:43:26Z

2

Definitely the shortest version:

$max_array = array_map('max', $arr1);

array_map() takes each element array of $arr1 and applies max() to it.

Edited after seeing that max in each column position is desired:

$sorted = array();
for ($i = 0; $i <=2; $i++) { 
    $sorted[$i] = array_column($input, $i);
}

This loops over the array and applies array_column() to each (requires PHP 5.5).

So:

$sorted = array();
for ($i = 0; $i <=2; $i++) { 
    $sorted[$i] = array_column($arr1, $i);
}
$max_array = array_map('max', $sorted);

working version

edited Feb 4, 2014 at 14:43

answered Feb 4, 2014 at 14:14

Digital Chris

6,1771 gold badge22 silver badges29 bronze badges

1 Comment

rccoros Over a year ago

OP wanted to get the max of each column so @Mario Johnathan's answer is better.

George Lund · Accepted Answer · 2014-02-04 14:15:51Z

0

You only need one loop, because the max function takes an array as a parameter. But the answer you are giving is wrong, unless I've misunderstood the problem.

I think what you're after is:

$max_array = array_map('max', $arr1);

answered Feb 4, 2014 at 14:15

George Lund

1,28412 silver badges16 bronze badges

Comments

mickmackusa · Accepted Answer · 2020-03-08 10:50:48Z

All of the earlier answers are working too hard.

Use array_map() as the iterating function.
Unpack your multidimensional array with the "spread/splat operator" (...); in other words, convert your single array containing three subarrays into three separate arrays.
Call max() on the three elements as they are synchronously iterated by array_map().

Code: (Demo)

$arr1 = [
    [1, 2, 3],
    [2, 4, 6],
    [25, 4, 5],
];

var_export(array_map('max', ...$arr1));

The above is a more versatile and concise version of the following one-liner which has the same effect on the sample array:

var_export(array_map('max', $arr1[0], $arr1[1], $arr1[2]));

Output:

array (
  0 => 25,
  1 => 4,
  2 => 6,
)

*A note for researchers: if processing a multidimensional array that has associative first level keys, you will need to index the first level so that the splat operator doesn't choke on the keys.

...array_values($array)

Collectives™ on Stack Overflow

maximum value in php array for each key value

5 Answers 5

1 Comment

Comments

1 Comment

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

1 Comment

Comments

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related