| Introduction to Web Development |
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| Basic PHP Syntax |
|---|
| PHP Basics |
|---|
| Variables and Data Types |
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| Functions in PHP |
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| User-defined Functions |
|---|
| Built-in Functions |
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| Variable Scope |
|---|
| Include and Require |
|---|
| Working with Forms |
|---|
| Forms in HTML |
|---|
| Form Handling in PHP |
|---|
| Working with Files |
|---|
| File Handling |
|---|
| File System Functions |
|---|
| Working with Databases |
|---|
| Introduction to Databases |
|---|
| Advanced PHP Techniques |
|---|
| Object-Oriented Programming (OOP) |
|---|
| Error and Exception Handling |
|---|
Built-in array functions in PHP are a set of powerful tools that allow developers to manipulate and manage arrays efficiently. Here’s an in-depth look at some of the most commonly used array functions in PHP:
1. array()
Creates an array.
$arr = array(1, 2, 3, 4);
2. array_change_key_case()
Changes all keys in an array to lowercase or uppercase.
$array = array("A" => 1, "B" => 2);
$array = array_change_key_case($array, CASE_LOWER);
3. array_chunk()
Splits an array into chunks of new arrays.
$array = array(1, 2, 3, 4, 5);
$chunks = array_chunk($array, 2);
4. array_column()
Returns the values from a single column in the input array.
$records = array(
array(
'id' => 2135,
'first_name' => 'John',
'last_name' => 'Doe',
),
array(
'id' => 3245,
'first_name' => 'Sally',
'last_name' => 'Smith',
),
);
$first_names = array_column($records, 'first_name');
5. array_combine()
Creates an array by using one array for keys and another for its values.
$a = array('green', 'red', 'yellow');
$b = array('avocado', 'apple', 'banana');
$c = array_combine($a, $b);
6. array_count_values()
Counts all the values of an array.
$array = array(1, "hello", 1, "world", "hello");
$counted_values = array_count_values($array);
7. array_diff()
Computes the difference of arrays.
$array1 = array("a" => "green", "red", "blue", "red");
$array2 = array("b" => "green", "yellow", "red");
$result = array_diff($array1, $array2);
8. array_filter()
Filters elements of an array using a callback function.
$input = array("a" => 1, "b" => 2, "c" => 3, "d" => 4);
$result = array_filter($input, function($value) {
return $value > 2;
});
9. array_flip()
Exchanges all keys with their associated values in an array.
$array = array("a" => 1, "b" => 2, "c" => 3);
$flipped = array_flip($array);
10. array_key_exists()
Checks if the given key or index exists in the array.
$array = array("first" => 1, "second" => 4);
if (array_key_exists("first", $array)) {
echo "Key exists!";
}
11. array_keys()
Returns all the keys or a subset of the keys of an array.
$array = array(0 => 100, "color" => "red");
$keys = array_keys($array);
12. array_map()
Applies the callback to the elements of the given arrays.
$func = function($value) {
return $value * $value;
};
$array = array(1, 2, 3, 4, 5);
$result = array_map($func, $array);
13. array_merge()
Merges one or more arrays.
$array1 = array("color" => "red", 2, 4);
$array2 = array("a", "b", "color" => "green", "shape" => "trapezoid", 4);
$result = array_merge($array1, $array2);
14. array_pop()
Pops the element off the end of the array.
$array = array("red", "green", "blue");
$popped_value = array_pop($array);
15. array_push()
Pushes one or more elements onto the end of the array.
$array = array("red", "green");
array_push($array, "blue", "yellow");
16. array_reverse()
Returns an array with elements in reverse order.
$input = array("php", 4.0, array("green", "red"));
$reversed = array_reverse($input);
17. array_search()
Searches the array for a given value and returns the corresponding key if successful.
$array = array(0 => 'blue', 1 => 'red', 2 => 'green', 3 => 'red');
$key = array_search('green', $array);
18. array_shift()
Shifts an element off the beginning of the array.
$array = array("red", "green", "blue");
$shifted_value = array_shift($array);
19. array_slice()
Extracts a slice of the array.
$input = array("a", "b", "c", "d", "e");
$slice = array_slice($input, 2);
20. array_splice()
Removes a portion of the array and replaces it with something else.
$input = array("red", "green", "blue", "yellow");
array_splice($input, 2);
21. array_sum()
Returns the sum of values in an array.
$array = array(2, 4, 6, 8);
$sum = array_sum($array);
22. array_unique()
Removes duplicate values from an array.
$array = array("a" => "green", "red", "b" => "green", "blue", "red");
$result = array_unique($array);
23. array_unshift()
Prepends one or more elements to the beginning of an array.
$array = array("blue", "green");
array_unshift($array, "red", "yellow");
24. array_values()
Returns all the values of an array.
$array = array("size" => "XL", "color" => "gold");
$values = array_values($array);
25. array_walk()
Applies a user function to every member of an array.
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");
function test_alter(&$item1, $key, $prefix)
{
$item1 = "$prefix: $item1";
}
array_walk($fruits, 'test_alter', 'fruit');
These functions represent only a portion of PHP’s extensive array manipulation capabilities. By understanding and utilizing these functions, developers can effectively manage and transform arrays, making their code more efficient and readable.
