我该如何替换＆lt;使用＆gt; =和＆gt; ＆lt; =并替换＆lt; = with＆gt;和＆gt; =与＆lt;如果它们在同一个字符串中多次出现？

Question

我正在使用PHP进行此操作。我有一个像这样的字符串： “AND day_1＆gt; = day_2 AND day_1＆lt; day_3” 我想替换第一个＆gt; = with＆lt;我想替换第二个＆lt;使用＆gt; =

换句话说，我想颠倒日期范围逻辑：

“AND day_1＆gt; = day_2 AND day_1＆lt; day_3”

我想反过来看起来像这样：

“AND day_1＆lt; day_2 AND day_1＆gt; = 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＆gt; = day_2 AND day_1＆lt; day_3 替换后：AND day_1＆lt; == day_2 AND day_1＆lt; == day_3

Answer 1

试试这个：

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