使用带有PHP的正则表达式检查段落中的一些表达式

Question

I want to use regular expressions in PHP to check if a text has at least two paragraphs, the first beginning with "In fact" and another beginning with "I suggest."

  For example, I tested this:

$text = "In fact Paris is more beautiful than Berlin.
I suggest we go to Paris this summer."
$value = preg_match ( "/ (^ In fact (.))  (I suggest). * /", $text);
echo $value;
I get $value = 0;

I get $value = 0;

I do not know why, please help.

Answer 1

This should work.

$text = "In fact Paris is more beautiful than Berlin.
I suggest we go to Paris this summer.";
if(preg_match ( "/^In fact(.*)I suggest/s", $text)){
echo 'true';
} else {
echo 'false';
}

In your regex this . * is allowing one of any characters . then any number of spaces *. This (.) is allowing one space.

I'm not seeing what you are trying to capture so I removed your capture groups. The s modifier allows the . to match new lines.

Regex Demo: https://regex101.com/r/vW2oZ8/1
PHP Demo: https://eval.in/584773