Detailed explanation of PHP array function examples

Array functions in PHP are very useful for processing arrays. In this article, we will take a closer look at some of the most commonly used array functions.

1. array_push()

The array_push() function can push one or more elements to the end of the array. The syntax is as follows:

array_push($array, $value1, $value2, ...);

Example:

$fruits = array("apple", "banana");
array_push($fruits, "orange", "watermelon");
print_r($fruits);

Output:

Array
(
    [0] => apple
    [1] => banana
    [2] => orange
    [3] => watermelon
)

2. array_pop()

array_pop() function can pop An element at the end of the array and returns the value of that element. The syntax is as follows:

array_pop($array);

Example:

$fruits = array("apple", "banana", "orange", "watermelon");
$pop = array_pop($fruits);
echo $pop; //输出：watermelon
print_r($fruits);

Output:

Array
(
    [0] => apple
    [1] => banana
    [2] => orange
)

3. array_shift()

array_shift() function can Removes the element at the beginning of the array and returns the value of that element. The syntax is as follows:

array_shift($array);

Example:

$fruits = array("apple", "banana", "orange", "watermelon");
$shift = array_shift($fruits);
echo $shift; //输出：apple
print_r($fruits);

Output:

Array
(
    [0] => banana
    [1] => orange
    [2] => watermelon
)

4. array_unshift()

array_unshift() function can One or more elements are added to the beginning of the array. The syntax is as follows:

array_unshift($array, $value1, $value2, ...);

Example:

$fruits = array("apple", "banana", "orange");
array_unshift($fruits, "watermelon", "kiwi");
print_r($fruits);

Output:

Array
(
    [0] => watermelon
    [1] => kiwi
    [2] => apple
    [3] => banana
    [4] => orange
)

5. array_reverse()

array_reverse() function can The order of elements in the array is reversed. The syntax is as follows:

array_reverse($array);

Example:

$fruits = array("apple", "banana", "orange", "watermelon");
$reverse_fruits = array_reverse($fruits);
print_r($reverse_fruits);

Output:

Array
(
    [0] => watermelon
    [1] => orange
    [2] => banana
    [3] => apple
)

6. array_slice()

array_slice() function can be obtained from Get a fragment from an array. The syntax is as follows:

array_slice($array, $offset, $length);

Among them, $offset indicates the position where slicing is to begin, and $length indicates the length of slicing.

Example:

$fruits = array("apple", "banana", "orange", "watermelon");
$sliced_fruits = array_slice($fruits, 1, 2);
print_r($sliced_fruits);

Output:

Array
(
    [0] => banana
    [1] => orange
)

7. array_splice()

array_splice() function can replace or delete elements in an array A fragment into which new elements can be inserted. The syntax is as follows:

array_splice($array, $offset, $length, $replace_array);

Among them, $offset represents the position where the operation is to be started, $length represents the number of elements to be replaced or deleted, and $replace_array represents the element to be inserted. If no new elements need to be inserted, the $replace_array parameter can be omitted.

Example:

$fruits = array("apple", "banana", "orange", "watermelon");
array_splice($fruits, 1, 2, array("kiwi", "grape"));
print_r($fruits);

Output:

Array
(
    [0] => apple
    [1] => kiwi
    [2] => grape
    [3] => watermelon
)

8. array_key_exists()

array_key_exists() function checks whether an array exists The specified key. The syntax is as follows:

array_key_exists($key, $array);

Among them, $key is the key to be checked, and $array is the array to be checked.

Example:

$fruits = array("apple" => 1, "banana" => 2, "orange" => 3);
if (array_key_exists("banana", $fruits)) {
    echo "存在";
} else {
    echo "不存在";
}

Output: exists

In addition, there are many other array functions, such as array_map(), array_filter(), array_reduce(), etc. Mastering these functions allows us to process arrays in PHP more efficiently.

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