如何將<< with > =和>替換爲<=，並用<替換爲<= with >和> =如果它們在同一個字符串中出現多次？

Question

我正在使用PHP工作。我有一個這樣的字符串： 「AND day_1> = day_2和day_1 < day_3」 ，我想，以取代第一> =與<，我想替換第二<與> =

換句話說，我想扭轉日期範圍邏輯：

「AND day_1> = day_2和day_1 < day_3」

我想逆轉這個樣子：

「AND day_1 < day_2和day_1> = day_3 「

這裏是我的代碼：

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

當我嘗試使用字符串替換它這樣做：

之前更換：AND day_1> = day_2和day_1 < day_3 後替換：AND day_1 < = = day_2和day_1 < == day_3

Answer 1

試試這個：

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