Question

How do you do a regex in php that finds a space that has a letter on its left and a number on its right?

I have done many of these over the last day and at best I can find the “letter space number” combo, but I do not know how to find just the space between the letter and number. I would like to replace this space with a comma.

E.G:

The big red Fox 283 brown balls

would be converted to:

The big red Fox,283 brown balls

Thank you in advance for answering this question. If you provide an explanation with how the answer works it would be greatly appreciated.

Answer 1

You can use the preg_replace function to do this:

$string = 'The big red Fox 283 brown balls';
preg_replace('/([a-zA-Z]) ([0-9])/', '$1,$2', $string);

The [a-zA-Z] part of the regex matches any letter, and the [0-9] matches any digit. Together, /[a-zA-Z] [0-9]/ means that we want to match any letter followed by a space, followed by a digit.

The circle brackets denote backreferences, which allows parts of the original string to be “remembered” (in the variables $1 and $2) so that we can include those matched strings in the replacement string.