PHP quirks and pitfalls [closed]

Answer 1

Although strings may be iterated using for loops and indexes, they can't be iterated using foreach loops. Example:

$str = 'foo';
$max = strlen($str);

for ($i=0; $i<$max; $i++)  {
    echo $str[$i];
}
// outputs: foo

foreach ($str as $char) {
    echo $char;
}
// Warning: Invalid argument supplied for foreach() ...