使用php检查字符串是否包含10位数字，但每个数字后面有空格

Question

Suppose

$str = "hi hello 1 2 3 4 5 6 7 8 9 0 ok"

so the match found. I have tried with regex like

preg_match_all('/[0-9 ]{20}/', $str, $matches, PREG_OFFSET_CAPTURE);
print_r($matches);

but it matches others also

Answer 1

Try using the following pattern:

\b[0-9](?: [0-9]){9}\b

Your updated code:

$str = "hi hello 1 2 3 4 5 6 7 8 9 0 ok";
preg_match_all('/\b[0-9](?: [0-9]){9}\b/', $str, $matches, PREG_OFFSET_CAPTURE);
print_r($matches[0][0]);

Array ( [0] => 1 2 3 4 5 6 7 8 9 0 [1] => 9 )

The reason for placing the word boundaries ( \\b ) around both sides of the pattern is to prevent a false match along the lines of the following

10 2 3 4 5 6 7 8 9 0
1 2 3 4 5 6 7 8 9 012

That is, we need to make sure that the first and final digits are in fact single digits by themselves, and not parts of larger numbers.

Answer 2

Try this !

Regex :

(?:[0-9][ ]){10}

Verify through regex101 :

Answer 3

your regex is matching space before the first number, that is the problem

[0-9 ]{20}

To correct it by starting with [0-9] you enforce the first match to be a number and adjust a space followed by a number( [ ][0-9] ) 9 times.

[0-9](?:[ ][0-9]){9}

demo