How to extract a number from a string in PHP using preg_replace()

Sometimes all you need from a string are certain elements. Such an element can be a hidden number which has significance to you. Maybe a timestamp for instance.

Here then is how you can lift various numbers from a string using preg_replace() and a well defined regular expression. First let us have a look at the regular expression itself.

It has a negative quality thanks to the [^, meaning it is looking for anything that is not a number. The \d stands for decimal, while the \s stands for whitespaces, therefore all the gaps inside the string will be maintained.


For no gaps to remain between the numbers simply remove the \s:


Now that we have discussed the regular expression itself we can move on to the preg_replace() and the rest of the code. Notice how we have a string with numerous numerical values inside it. They will all first be removed, then we will echo the string: