比较嵌套 foreach 中的数组值 - Comparing array values in nested foreach

Comparing array values in nested foreach

本文关键字：数组嵌套 foreach 比较 | 更新日期: 2023-09-27

我有两个数组：

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

我想像这样打印这个数组：

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

她是我的代码：

$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>";
    }
}

结果是：

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

您需要将

echo移出循环。

$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>";
    }
}

使用 in_array() 检查数组中是否存在值。

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

如果您不想使用in_array()函数：

$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

你应该试试这个：

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

$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 />";
    }
}