foreach($array as $key => $array) 時の動作 ref: http://qiita.com/khsk/items/ea22c035232123804303

file1.txt

key: A array: a
array[key]: a
string(1) "a"
key: B array: 100
array[key]:
int(100)
key: C array: 1 # true は出力で1
array[key]:
bool(true)
bool(true)

file3.txt

array: a
string(1) "a"
array: 100
int(100)
array: 1
bool(true)
bool(true)

file5.txt

key: 0 array: a
array[key]: a
string(1) "a"
key: 1 array: 100
array[key]:
int(100)
key: 2 array: 1
array[key]:
bool(true)
bool(true)

file7.txt

key: 0 array: a
array[key]: a
string(1) "a"
key: 1 array: b
PHP Notice:  Uninitialized string offset: 1 in /tmp/foreach4.php on line 47
array[key]:
string(1) "b"
key: 2 array: c
PHP Notice:  Uninitialized string offset: 2 in /tmp/foreach4.php on line 47
array[key]:
string(1) "c"
string(1) "c"

foreach1,php

$array = array('A' => 'a', 'B' => 100, 'C' => true);

foreach ($array as $key => $array) {
    echo "key: " . $key . " array: " . $array . "\n";
    echo "array[key]: " . $array[$key] . "\n";
    var_dump($array);
}

var_dump($array);

foreach2,php

$array = array('A' => 'a', 'B' => 100, 'C' => true);

foreach ($array as $array) {
    echo "array: " . $array . "\n";
    var_dump($array);
}

var_dump($array);

foreach3.php

$array = array('a', 100, true);

foreach ($array as $key => $array) {
    echo "key: " . $key . " array: " . $array . "\n";
    echo "array[key]: " . $array[$key] . "\n";
    var_dump($array);
}

var_dump($array);

foreach4.php

$array = array('a', 'b', 'c');

foreach ($array as $key => $array) {
    echo "key: " . $key . " array: " . $array . "\n";
    echo "array[key]: " . $array[$key] . "\n";
    var_dump($array);
}

var_dump($array);