php正则表达式在字符串中查找符号[关闭]

Question

How in a string

-1 -2 -3 -4

get

array(-1, -2, -3, -4)

using regex and function

preg_match_all

Any help is appreciated! Thanks!

Answer 1

Use this:

/(([-]?\d+))/gmi

The result:

MATCH 1
1.  [1-3]   `-1`
MATCH 2
1.  [8-10]  `-2`
MATCH 3
1.  [15-17] `-3`
MATCH 4
1.  [22-24] `-4`

See demo

In PHP usage:

  $string = '(-1) * (-2) - (-3) * (-4)';
  $regex = '/(([-]?\d+))/i';

  preg_match_all($regex, $string, $matches);

  print_r($matches[1]);

Result:

Array ( [0] => -1 [1] => -2 [2] => -3 [3] => -4 )