PHP正则表达式首先提取嵌套表达式然后是外部表达式

Question

I am having a problem with bit of code.

This is the code

$test ='<number>1<number>2</number>3</number>';

$i=0;
$find[$i]="#<number>(.*)</number>#is";
$replace[$i]="5";

$i++;
$find[$i]="#<number>(.*)</number>#is";
$replace[$i]="$1";


echo htmlentities(preg_replace($find, $replace, $test));

At the moment this displays just the numnber 5 in the results. But i want it to display 153 Does anyone know what I am doing wrong? thanks

Answer 1

Yes, since .* matches everything (including the tags), you're matching too much. If you restrict your regex not to match across tag boundaries by preventing it from matching angle brackets, you get the desired result:

$test ='<number>1<number>2</number>3</number>';

$i=0;
$find[$i]="%<number>([^<>]*)</number>%is";
$replace[$i]="5";

$i++;
$find[$i]="%<number>([^<>]*)</number>%is";
$replace[$i]="$1";

Answer 2

将第一个替换模式更改为：

$find[$i] = "#<number>\d+<number>(.*)</number>\d+</number>#is";

Answer 3

$s ='<number>1<number>2</number>3</number>'; 
echo preg_replace('#<number>(\d+)<number>\d+</number>(\d+)</number>#', "$1 5 $2", $s);

Test code here .