In PHP development, we often need to process arrays and strings, such as splitting, merging, replacing, etc. PHP has many built-in functions that can easily complete these operations. This article will focus on PHP's own methods of processing arrays and strings, so that readers can become more proficient in using PHP for development.
1.1 array_filter()
array_filter() can filter the elements in the array and determine which elements are based on certain judgment conditions Which should be retained and which should be eliminated. The function is defined as follows:
array array_filter ( array $array [, callable $callback [, int $flag = 0 ]] )
Among them, $array represents the array to be filtered, $callback is an optional parameter, indicating the filtering conditions, and $flag is an optional parameter, indicating which parameter to use for filtering.
For example, we can filter out empty elements in the array through array_filter():
$values = array('','value1','value2','','value3'); $result = array_filter($values); print_r($result);
The output result is:
Array ( [1] => value1 [2] => value2 [4] => value3 )
1.2 array_map()
The array_map() function can process elements in one or more arrays and return the result array. The function is defined as follows:
array array_map ( callable $callback , array $array1 [, array $... ] )
Among them, $callback represents the callback function for processing elements, $array1 represents the array to be processed, and multiple arrays can be passed in.
For example, we can multiply all elements in the array by 2 through array_map():
$values = array(1,2,3,4,5); $result = array_map(function($value){ return $value*2; }, $values); print_r($result);
The output result is:
Array ( [0] => 2 [1] => 4 [2] => 6 [3] => 8 [4] => 10 )
1.3 array_sum()
array_sum() function can calculate the sum of all elements in an array. The function is defined as follows:
number array_sum ( array $array )
Among them, $array represents the array to be summed.
For example, we can use array_sum() to calculate the sum of all elements in the array:
$values = array(1,2,3,4,5); $result = array_sum($values); echo $result;
The output result is:
15
2.1 explode()
The explode() function can split a string into an array according to the specified delimiter. The function is defined as follows:
array explode ( string $delimiter , string $string [, int $limit = PHP_INT_MAX ] )
Among them, $delimiter represents the delimiter, $string represents the string to be split, and $limit represents the maximum number of elements to be split. If this parameter is not passed in, it will be split by default. Divided into infinite elements.
For example, we can use explode() to split a string into an array based on commas:
$string = 'apple,banana,orange,pear'; $result = explode(',', $string); print_r($result);
The output result is:
Array ( [0] => apple [1] => banana [2] => orange [3] => pear )
2.2 implode()
implode() function can concatenate an array into a string. The function is defined as follows:
string implode ( string $glue , array $pieces )
Among them, $glue represents the connector and $pieces represents the array to be spliced.
For example, we can use implode() to splice an array into a string based on commas:
$values = array('apple', 'banana', 'orange', 'pear'); $result = implode(',', $values); echo $result;
The output result is:
apple,banana,orange,pear
2.3 str_replace()
str_replace() function can replace a certain substring in a string with another substring. The function is defined as follows:
mixed str_replace ( mixed $search , mixed $replace , mixed $subject [, int &$count ] )
Among them, $search represents the substring to be replaced, $replace represents the substring used for replacement, $subject represents the string to be operated on, $count represents the number of replacements, if not If this parameter is passed in, all matching substrings will be replaced by default.
For example, we can use str_replace() to replace all spaces in a string with underscores:
$string = 'this is a test string'; $result = str_replace(' ', '_', $string); echo $result;
The output result is:
this_is_a_test_string
Summary
This article introduces some common methods for processing arrays and strings that come with PHP, such as array filtering, array mapping, array summation, string splitting, string splicing, string replacement and other operations. I hope that readers can become more proficient in using PHP for development and improve development efficiency by studying this article.
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