How To Add To Array With PHP – 6 Ways

Arrays are fundamental data structures in PHP, providing a means to store, manage, and manipulate collections of data. Whether you’re developing complex web applications or simple scripts, understanding the various ways to add elements to an array is crucial for efficient and readable code. In this comprehensive guide, we’ll explore different methods to add elements to an array in PHP, highlighting their syntax, usage, and examples.

Introduction to PHP Arrays
Adding Elements to an Array
Conclusion
References

Introduction to PHP Arrays

PHP arrays are versatile and can store various types of data, including strings, numbers, objects, and even other arrays. Arrays can be indexed, associative, or multidimensional. Here’s a quick overview of these types:

Indexed Arrays: Arrays with numeric indexes $fruits = ['apple', 'banana', 'cherry'];
Associative Arrays: Arrays with named keys $ages = ['Peter' => 35, 'John' => 42];
Multidimensional Arrays: Arrays containing one or more arrays $matrix = [ [1, 2, 3], [4, 5, 6], [7, 8, 9] ];

Adding Elements to an Array

Using the `array_push()` Function

The array_push() function is a common and straightforward method to add one or more elements to the end of an array.

array_push Function Syntax:

array_push(array &$array, mixed ...$values): int

Example usage:

$myArray = ['mySimpleArrayEntry1', 'mySimpleArrayEntry2', 'mySimpleArrayEntry3']; // Create the initial array
array_push($myArray , 'mySimpleArrayEntry4', 'mySimpleArrayEntry5'); // push to the array using array_push()
print_r($myArray);

Output:

Array
(
    [0] => mySimpleArrayEntry1
    [1] => mySimpleArrayEntry2
    [2] => mySimpleArrayEntry3
    [3] => mySimpleArrayEntry4
    [4] => mySimpleArrayEntry5
)

Using the `[]` (Square Bracket) Syntax

The square bracket syntax is a concise and efficient way to add elements to the end of an array. This method is particularly useful for adding a single element. And, to be honest, it’s one of my personal favorite ways to add to an array.

Example:

$animals = ['dog', 'cat']; // Create initial array
$animals[] = 'parrot'; // push to the end of the array
print_r($animals);

Output:

Array
(
    [0] => dog
    [1] => cat
    [2] => parrot
)

Using the `array_unshift()` Function

The array_unshift() function adds one or more elements to the beginning of an array, shifting existing elements to higher indexes. This can be particularly useful in certain use-cases.

array_unshift Function Syntax:

array_unshift(array &$array, mixed ...$values): int

Example:


$fruits = array("pear", "kiwi", "apple");// create the initial array
array_unshift($fruits, "orange", "melon"); // Add elements to the beginning of the array
print_r($fruits);

Output:

Array
(
    [0] => orange
    [1] => melon
    [2] => pear
    [3] => kiwi
    [4] => apple
)

Using the `array_merge()` Function

The array_merge() function combines one or more arrays, effectively adding elements from the specified arrays to the end of the first array. This is quite a powerful feature, especially with data analysis.

Cool note:

There is no limit on the number of arrays that can be merged with array_merge() as long as you stay within the memory limits of your PHP configuration and environment.

Syntax:

array_merge(array ...$arrays): array

Example:

$array1 = ['x', 'y'];
$array2 = ['a', 'b'];
$array3 = ['1', '2'];
$result = array_merge($array1, $array2, $array3);
print_r($result);

Output:

Array
(
    [0] => x
    [1] => y
    [2] => a
    [3] => b
    [4] => 1
    [5] => 2
)

Using the `+` (Union) Operator

The union operator (+) adds elements from the second array to the first array only if the keys are not already present in the first array. Although I’m struggling with how this one could come in handy, I’m sure it will serve some good purpose in some projects.

Example:

$array1 = ['a', 'b'];
$array2 = ['c', 'd', 'a' => 'e'];
$result = $array1 + $array2;
print_r($result);

Output:

Array
(
    [0] => a
    [1] => b
    [a] => e
    [2] => d
)

Using the `array_splice()` Function

The array_splice() function can insert elements at any position within an array, not just at the beginning or end. Another powerful way of adding to an array with PHP –

Syntax:

array_splice(array &$array, int $offset, int $length = 0, mixed $replacement = []): array

Example:

$letters = ['a', 'c', 'd']; // Create initial Array
array_splice($letters, 1, 0, 'b'); // add the letter b to the array at index 1
print_r($letters);

Heres is a screenshot from PHPStorm code editor, which is a bit more easier to understand (Notice the offset and length)

Output:

Array
(
    [0] => a
    [1] => b
    [2] => c
    [3] => d
)

In-Depth Examples and Use Cases

Combining Multiple Methods

Sometimes, combining multiple methods to add elements to an array can be beneficial. For instance, you might want to add elements at both the beginning and the end of an array. Then finally, merge that array with another.

Example:

$initialArray = ['middle1', 'middle2']; // create initial array
array_unshift($initialArray, 'start1', 'start2'); // Add to beginning of array
array_push($initialArray, 'end1', 'end2'); // Add to end of array
print_r(array_merge($initialArray, ["merged1", "merged2"])); // print array, but first merge it with another array

Output:

Array
(
    [0] => start1
    [1] => start2
    [2] => middle1
    [3] => middle2
    [4] => end1
    [5] => end2
    [6] => merged1
    [7] => merged2
)

Performance Considerations

When adding elements to arrays, performance can vary based on the method used and the size of the array. Here are a few tips to optimize performance:

Use [] for Single Elements: The [] syntax is generally the fastest for adding single elements to the end of an array. – I always opt for this in the given use case.
Prefer array_push() for Multiple Elements: While array_push() is slightly slower than [] for a single element, it’s efficient for adding multiple elements.
Avoid array_merge() for Large Arrays: array_merge() can be slower and consume more memory for large arrays due to the creation of a new array.
Check for Duplicates Efficiently: When ensuring unique elements, use associative arrays to leverage the faster array_key_exists() function instead of in_array().

Conclusion

Mastering the various ways to add elements to an array in PHP is essential for writing efficient and maintainable code. From the simplicity of the square bracket syntax to the versatility of array_splice(), each method has its unique advantages and use cases. By understanding and utilizing these methods appropriately, you can handle array manipulations with ease, ensuring your PHP applications are robust and performant.

Explore these techniques in your projects to determine which best fits your needs and enhances your coding workflow. Whether you’re adding elements conditionally, ensuring uniqueness, or managing large datasets, PHP provides a rich set of tools to help you manage arrays effectively.

How To Add To Array With PHP – 6 Ways