如果条件不能正常工作，则在php中进行字符串比较

$str1 = "Hello";
$str2 = "Hello";

if ($str1 == $str2) {
    echo "Strings are equal";
} else {
    echo "Strings are not equal";
}

$str1 = "123";
$str2 = 123;

if ($str1 === $str2) {
    echo "Strings are equal";
} else {
    echo "Strings are not equal";
}

$str1 = "abc";
$str2 = "def";

$result = strcmp($str1, $str2);

if ($result < 0) {
    echo "Str1 is less than Str2";
} elseif ($result > 0) {
    echo "Str1 is greater than Str2";
} else {
    echo "Str1 is equal to Str2";
}

$str = "Hello, world!";

if (strpos($str, "world") !== false) {
    echo "Substring found";
} else {
    echo "Substring not found";
}