Comparing array values in nested foreach

Question

I've two arrays:

$rooms = [1,2,3,4,5,6,7,8,9];
$reserved_rooms = [4, 7];

I would like to print this array like this:

1
2
3
Room 4 is reserved
5
6
Room 7 is reserved

Her is my code:

$rooms = [1,2,3,4,5,6,7,8,9];
$reserved_rooms = [4, 7]; 

foreach($rooms as $key=>$val){
    foreach($reserved_rooms as $val2){
        if($val == $val2){
            echo $val2." room is reserved";
        }   
        else
            echo $val."<br>";
    }
}

The result is:

1
1
2
2
3
3
4 room is reserved4
5
5
6
6
7
7 room is reserved8
8
9
9

In reaction to the comments on the answers. Specify a dummy but correct example. This will make it easier to help you find the best solution. Iterating over arrays is time consuming and probably not necessary. — RST
– RST, Commented Jan 27, 2016 at 11:23

Federkun · Accepted Answer · 2016-01-27 10:58:20Z

4

You need to move your echo outside the loop.

$rooms = [1,2,3,4,5,6,7,8,9];
$reserved_rooms = [4, 7]; 

foreach($rooms as $key=>$val){
    $isReserved = false; // add this

    foreach($reserved_rooms as $val2){
        if($val == $val2){
            $isReserved = true;
            break; // is reserved, no need to check the other values
        }
    }

    if ($isReserved) { // now decide whether it is reserved or not
        echo $val." room is reserved";
    } else {
        echo $val."<br>";
    }
}

answered Jan 27, 2016 at 10:58

Federkun

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Comments

ʰᵈˑ · Accepted Answer · 2016-01-27 10:54:20Z

3

Use in_array() to check if a value exists in the array.

foreach($rooms as $room) {
   if( in_array($room, $reserved_rooms) ) {
      echo $room .' is reserved.' . PHP_EOL;
      continue;
   }
   echo $room . PHP_EOL;
}

https://eval.in/508706

answered Jan 27, 2016 at 10:54

ʰᵈˑ

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6 Comments

Sarvar Nishonboyev Over a year ago

yeah, you are right. but is it possible to do not using in_array() function?

ʰᵈˑ Over a year ago

...why do you not want to use a native function?

Florian Humblot Over a year ago

@ʰᵈˑ wouldn't continue also echo the second echo ? Sorry if I'm mistaken

ʰᵈˑ Over a year ago

No, continue will finish that iteration and move on to the next

Sarvar Nishonboyev Over a year ago

My problem is I can't use in_array(), coz it's other type comparison, not exact value. I just give this example to explain more simple

|

Alexander · Accepted Answer · 2016-01-27 11:40:45Z

1

In case you do not want to use in_array() function :

$rooms = [1,2,3,4,5,6,7,8,9];
$reserved_rooms = [4, 7]; 

array_map(function ($room) use ($reserved_rooms) { 
    foreach($reserved_rooms as $reserved_room) {
       if ($reserved_room == $room) { 
           print "Room $room is reserved\n";
           return;
       }
    }
    print "$room\n"; 
}, $rooms);

https://eval.in/508743

edited Jan 27, 2016 at 11:40

answered Jan 27, 2016 at 11:23

Alexander

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Comments

Florian Humblot · Accepted Answer · 2016-01-27 10:55:40Z

0

You should try this:

foreach($rooms as $key=>$val){
    if(in_array($val, $reserved_rooms){
        echo $val." room is reserved";
    }else{
        echo $val
    }
}

answered Jan 27, 2016 at 10:55

Florian Humblot

95511 silver badges33 bronze badges

Comments

Asif Jafri Mohammad Fahim · Accepted Answer · 2016-01-27 11:09:42Z

0

$rooms = [1,2,3,4,5,6,7,8,9];
$reserved_rooms = [4, 7]; 

foreach($rooms as $key=>$val){
    $flag = false;
    foreach($reserved_rooms as $val2){
        if($val == $val2){
            echo "Room ".$val2." is reserved<br />";
            $flag=true;
            break;
        }        
    }
    if($flag == false){
        echo $val."<br />";
    }
}

answered Jan 27, 2016 at 11:09

Asif Jafri Mohammad Fahim

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2 Comments

ʰᵈˑ Over a year ago

I like the part where it looks identical to stackoverflow.com/a/35035422/3000179. Plus, code-only answers are discouraged

Asif Jafri Mohammad Fahim Over a year ago

Please have a look at the code that you think identical. The accepted answer give output like 1 2 3 4 room is reserved5 6 7 room is reserved8 9 And my code give output like 1 2 3 Room 4 is reserved 5 6 Room 7 is reserved 8 9 That exactly what you want to print as described your question.

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