Since there is only 1 numeric value to isolate in your string, I would endorse and personally use filter_var[] with FILTER_SANITIZE_NUMBER_INT.
echo filter_var[$string, FILTER_SANITIZE_NUMBER_INT];
A whackier technique which works because there is only 1 numeric value AND the only characters that come before the integer are letters, colons, or spaces is to use ltrim[] with a character mask then cast the remaining string as an integer.
Demo
$string = "In My Cart : 11 items";
echo [int]ltrim[$string, 'A..z: '];
// 11
If for some reason there was more than one integer value and you wanted to grab the first one, then regex would be a direct technique.
Demo
echo preg_match['/\d+/', $string, $m] ? $m[0] : '';
sscanf[] is rather handy if you need to explicitly cast the numeric string as an integer [or float]. If it is possible/unknown for the integer value to occur at the start of the string, then prepend a non-numeric character to the input string before
scanning it. The following technique matches leading non-digits [and ignores them with * after the %], then matches the first occurring sequence of digits and casts the returned substring as an integer.
Demo
var_dump[sscanf[' ' . $string, '%*[^0-9]%d'][0]];
To adapt this technique to extract a float value, just change the d to f. For more information on the [currently undocumented] assignment suppression feature of
sscanf[], see this post.
In this article, we will extract numbers from strings using PHP. There are various built-in methods to extract numbers from strings, some of them are discussed below.
Methods:
- Using preg_match_all[] Function.
- Using filter_var[] Function.
- Using preg_replace[] function.
Method 1: Using preg_match_all[] Function.
Note: preg_match[] function is used to extract numbers from a string. Usually, the search starts from the beginning of the subject string. The optional parameter offset is used to specify the position from where to start the search.
Syntax:
int preg_match[ $pattern, $input, $matches, $flags, $offset ]
Return value: It returns true if a pattern exists, otherwise false.
Example 1: Thefollowing exampleextracts Integer Numbers using the preg_match_all[] function.
PHP
Output
Array
[
[0] => Array
[
[0] => 2
[1] => 4
]
]Example 2: The following example extracts decimal numbers using the preg_match_all[] function.
PHP
Output
Array
[
[0] => Array
[
[0] => 2
[1] => 4.8
]
]Method 2: Using filter_var[] function.
Note: The filter_var[] function filters a variable with the specified filter. This function is used to both validate and sanitize the data.
Syntax:
filter_var[var, filtername, options]
Return Value: It returns the filtered data on success, or FALSE on failure.
Example:
PHP
Output
The numbers are: 24
Method 3: Using preg_replace[] function.
Note: The preg_replace[] function is an inbuilt function in PHP that is used to perform a regular expression for search and replace the content.
Syntax:
preg_replace[ $pattern, $replacement, $subject, $limit, $count ]
Return Value: This function returns an array if the subject parameter is an array, or a string otherwise.
Example:
PHP
Output
The numbers are: 24