PHP: how to get numeric value of a string with multiple numbers? - php

Question

Let's say in PHP I have a string-variable : "This takes between 5 and 7 days"
I need to store some sensible information about the time it takes in an integer.
I'm satisfied if the result would be 5.
I tried stripping non-numeric characters, but end up with 57 then.
How can this be done in a better way?

Answer 1

Use preg_match to match the first digit group using a regex:
$subject = 'This takes between 5 and 7 days';
if (preg_match('/\d+/', $subject, $matches)) {
echo 'First number is: ' . $matches[0];
} else {
echo 'No number found';
}
Using preg_match_all you could match all digit groups (5 and 7 in this example):
$subject = 'This takes between 5 and 7 days';
if (preg_match_all('/\d+/', $subject, $matches)) {
echo 'Matches found:<br />';
print_r($matches);
} else {
echo 'No number found';
}

Answer 2

If you want to quantify the numbers appropriately, I would suggest the following:
<?php
$subject = "This takes between 5 and 7 days";
$dayspattern = '/\d+(\.\d+)? ?days?/';
$hourspattern = '/\d+(\.\d+)? ?hours?/'
$hours = -1;
if (preg_match($dayspattern , $subject, $matches) > 0)
{
preg_match($dayspattern, $matches[0], $days);
$hours = $days * 24;
} elseif (preg_match($dayspattern , $subject, $matches) > 0) {
preg_match($hourspattern, $matches[0], $hours);
$hours = $hours;
}
?>
You would need to consider:
what happens when no numbers are found, or numbers are given as text instead.
what happens when someone says '1 day and 5 hours'
Hopefully this gives you enough information to do the rest yourself.

Answer 3

If you would like to extract the price, ie €7.50 OR $50 etc
here is the regular expression comes to the solution for me.
preg_match('/\d+\.?\d*/',$price_str,$matches);
echo $matches[0];
results 7.50 OR 50

Answer 4

Seperate the subject into words by splitting the string into an array. Then, somehow I don't know, take the words out of the array. Maybe by looping through all children of the array inside a try-catch block, and try to change each element into an int type:
for($i=0;$i<$words->length;$i++){
try{
$tempNum = (int)$words[$i];
}catch($ex){
$words->remove($i);
}
}
Or something like that. I don't know any of the array methods, but you get what I mean. Anyway, the $words array now only contains numbers.