如何使用PHP替换不同的html代码？

Question

I have this HTML code in a PHP variable that I want to replace:

$text = "<table><tr><td>$something</td></tr><tr>
<td>$var1 $var2</td>
<td>$var3</td>
<td>$var4</td>
</tr><tr><td>$something</td></tr></table>";

I want to replace it with a concatenated HTML code:

$new_text = "<tr>
    <td>$new_var1 $new_var2</td>
    <td>$new_var3</td>
    <td>$new_var4</td>
    </tr>
<tr>
    <td>$new_var11 $new_var22</td>
    <td>$new_var33</td>
    <td>$new_var44</td>
    </tr>";

I am using str_replace to try to change them but it is not working, I also tried to do rtrim before doing the replace but still to no avail. Will anyone point me to what I am doing wrong here?

What have I tried using str_replace:

$new_text is my concatenated value

$text = str_replace("<tr>
    <td>$var1 $var2</td>
    <td>$var3</td>
    <td>$var4</td>
    </tr>", $new_text, $text);

I also tried:

 $text = str_replace("<tr>
        <td>$var1 $var2</td>
        <td>$var3</td>
        <td>$var4</td>
        </tr>", $new_text, htmlspecialchars($text));

Also:

 $text = rtrim($text);
 $text = str_replace("<tr>
        <td>$var1 $var2</td>
        <td>$var3</td>
        <td>$var4</td>
        </tr>", $new_text, htmlspecialchars($text));

All this are not working.

Answer 1

Don't use " double quotes for php variable string otherwise it will give warnings for variable. For replacing the string containing php variables you need to use nested str_replace and escape $ in str_replace.

$text = '<table><tr><td>$something</td></tr><tr>
<td>$var1 $var2</td>
<td>$var3</td>
<td>$var4</td>
</tr><tr><td>$something</td></tr></table>';
$search='<tr>
<td>$var1 $var2</td>
<td>$var3</td>
<td>$var4</td>
</tr>';
$new_text = '<tr>
    <td>$new_var1 $new_var2</td>
    <td>$new_var3</td>
    <td>$new_var4</td>
    </tr>
<tr>
    <td>$new_var11 $new_var22</td>
    <td>$new_var33</td>
    <td>$new_var44</td>
    </tr>';

echo str_replace(str_replace("\$","",$search),$new_text,str_replace("\$", "",$text));

Demo