Adding a <br> tag in a string after each 12 digit number

Question

I've a string from an HL7 message (lab results) and need to add a line break
after each 12 digit number.

Example string:

1    NM    2951-2  S Sodium:  LN     144    mmol/L  mmol/L    135-145       F      201402150533      2    NM    2823-3  S Potassium:  LN     5.6    mmol/L  mmol/L    3.5-5.5    H      F      201402150533      3    NM    2075-0  S Chloride:  LN     103    mmol/L  mmol/L    95-110       F      201402150533

As the 12 digit string is a date and timestamp this will change every test.

Answer 1

That is a good time to use a regular expression (see preg_replace):

$str = preg_replace('/\d{12}/', '$0<br>', $str);

replaces each string of 12 numerical digits, with that same string followed by <br>.