In the PHP development process, string processing is a crucial step. In string processing, regular expressions are also a very commonly used tool. When we need to convert a string into an array, we can use regular expressions to achieve this process very easily. This article will introduce how to use regular expressions to convert a string into an array.
1. Introduction to regular expressions
A regular expression is a pattern used to match strings. In PHP, we can use the preg_match() function to match strings. The preg_match() function has three parameters. The first parameter is the regular expression, the second parameter is the string to be matched, and the third parameter is used to store the matching result. If the match is successful, it will return 1, otherwise it will return 0. .
2. Convert a string into an array
In PHP, we can use regular expressions to easily convert a string into an array. The specific steps are as follows:
1. Determine the format of the string
Before converting the string into an array, we need to determine the format of the string. For example, suppose we want to convert the following string into an array:
$str = 'apple,orange,banana,grape';
Then the format of this string is a comma-separated list of Series value.
2. Write a regular expression
After determining the string format, we need to write a regular expression for matching. In this case, we need to match a comma separated range of values. Use the regular expression \d to match numbers, \w to match letters, and \s to match spaces. You can use [\w\s] to match a series of words or numbers. Use the regular expression /[\w\s] / to match such a series of words or numbers.
3. Implement the string to array function
Now that we have determined the format of the string and written the regular expression, we can convert the string into an array. The following is the specific PHP code implementation:
function str2arr($str) { preg_match_all("/[\w\s]+/", $str, $matches); return $matches[0]; } $str = 'apple,orange,banana,grape'; $arr = str2arr($str); print_r($arr);
Running the above code, we can get the following output:
Array ( [0] => apple [1] => orange [2] => banana [3] => grape )
3. Conclusion
Regular expression is a very powerful String processing tools. In PHP, we can use the preg_match() function to match strings, or we can use the preg_match_all() function to match all strings that match the rules. Using regular expressions to convert a string into an array can be very convenient. Extraordinarily simple code implementation allows you to quickly convert strings into arrays.
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