正则表达式 - 在字符串中查找8位数字[关闭]

Question

I want to extract 8 digit number from string using regex.

Test strings are

hi 82799162, 236232 (82342450), test data 8979

Required respective output should be

82799162, 82342450, null

I have tried following codes:

• preg_match('/[0-9]{8}$/', $string, $match);
• preg_match('/\d{8}$/', $string, $match);

But it does not retrieve the number from 236232 (82342450).

Answer 1

The problem is with your $ sign, and it is used to indicate the end of your expression. So basically, with that expression, you are looking for a string which ends with a 8 digit number. But in your second test string; '236232 (82342450)', ends with a bracket, and therefore it doesn't match the criteria (does not end with a number).

So remove the trailing $ and it will work.

preg_match('/[0-9]{8}/',$string,$match);

Hope it helps!!