php - 如果它们在同一个字符串中多次出现，如何将 < 替换为 >= 和 > 替换为 <= 并将 <= 替换为 > 和 >= 替换为 <？

Question

我正在用 PHP 做这个。我有一个这样的字符串：“AND day_1 >= day_2 AND day_1 < day_3”，我想用 < 替换第一个 >= ，我想用 >= 替换第二个 <

换句话说，我想反转日期范围逻辑：

“AND day_1 >= day_2 AND day_1 < day_3”

我想反转看起来像这样：

“AND day_1 < day_2 AND day_1 >= day_3”

这是我的代码：

$str = "AND day_1 >= day_2 AND day_1 < day_3";
echo "{$str}<br>";
$old_replace = array(">=", "<=", "<", ">");
$new_replace = array("<", ">", ">=", "<=");
$count = 1;
$str = str_replace($old_replace, $new_replace, $str, $count);
echo $str;

当我尝试使用字符串替换时，它会这样做：

替换前：AND day_1 >= day_2 AND day_1 < day_3 替换后：AND day_1 <== day_2 AND day_1 <== day_3

Answer 1

尝试这个：

$replacements = Array("<="=>">",">="=>"<","<"=>">=",">"=>"<=");
$str = strtr($str,$replacements);