PHP array_push() Function: How to Add Elements to Array
PHP add to array is an operation in which we append elements to the existing array. An array can contain many values under a single name, and you can access the values by referring to an index number.
In PHP, there are three types of array.
- Indexed arrays – Arrays with the numeric index.
- Associative arrays – Arrays with the named keys.
- Multidimensional arrays – Arrays that are containing one or more arrays.
Now, let’s see an example where we perform PHP to add to array operations.
PHP array_push() Function
PHP array_push() is a built-in function used to insert new items at the end of an array and get the updated array elements. The array_push() method takes a single element or an array of elements and appends it to the array.
You may add as many values as you need. Your inserted elements will always have numeric keys, even if the array itself has string keys. PHP array push() function has been introduced in PHP 4.
If we want to add more values to a PHP array, we need to use the array_push() function, which inserts one or more elements to the end of an array.
The length of the array increases by the number of variables pushed. You can add one element or multiple elements at a time using the array_push() function.
The array_push() treats an array as a stack and pushes the passed variables onto an array’s end.
The syntax for PHP Array Push is the following.
An array parameter is required in which we will add the value.
The value1 parameter is also required, which is the value we will insert into the specified array.
The value2, value3, and so on are optional parameters. However, if we want to add multiple values, we need to pass those parameters.
The array_push() function will return the length of new elements of an array.
Let’s see an example.
Create one file called app.php and add the following code.
<?php // app.php $netflix = ['Stranger Things', 'Black Mirror', 'Bright', 'XOXO']; $new = array_push($netflix, 'Shaft'); print_r($netflix); echo $new."\n";
In the above code, we have defined one array called $netflix, which has four items.
We have added the fifth item using the array_push() function in PHP and then print the original array and the return value from the array_push function.
Now, we are running the file on the terminal. So go to the terminal and navigate the app.php file directory and type the following command to run the file.
See the output.
That means we have successfully added the Shaft show to the $neflix array.
Also, the array_push() function returns the length of the array. In our case, it is 5. Remember, the PHP Array index is starting from 0.
This operation is also called PHP add to the array.
Adding multiple values to PHP array
PHP array_push() function takes multiple elements and appends all the elements into the array. It will add in the order that they are added. It does not change its order.
<?php // app.php $netflix = ['Stranger Things', 'Black Mirror', 'Bright', 'XOXO']; $new = array_push($netflix, 'Shaft', 'Mute', 'Clinical', 'Blue Jay', 'Candy Jar'); print_r($netflix); echo $new."\n";
The output is the following.
Adding values to the Associative Array
Let’s take a scenario where we are adding values to the Associative Array.
<?php // app.php $data = ['name' => 'Krunal', 'education' => 'BE']; $new = array_push($data, 'Ankit', 'MCA'); print_r($data); echo $new."\n";
See, the $data variable is Associative Array, and we have added two values to that array.
That means the first two items are associative, which have their key. But, from 3rd and 4th, they have indexes starting from 0. So, let’s run the PHP file and see the output.
Adding array into an array in PHP
Okay, now let’s take a scenario where we add a whole array inside an array and see the output.
<?php // app.php $dataA = ['name' => 'Krunal', 'education' => 'BE']; $second = ['Facebook', 'Instagram']; $newA = array_push($dataA, $second); print_r($dataA); echo $newA."\n";
The output is the following.
See, it has added an array as a 3rd element, and it has its index, which is 0 and 1.
So, right now, the dataA array is a multidimensional array.
Measuring PHP array length
<?php $netflix = ['Stranger Things', 'Black Mirror', 'Bright', 'XOXO']; echo count($netflix);
See the following output.
➜ pro php app.php 4 ➜ pro
That means we have four elements in the $netflix array. If we add more items inside the array, then the size of the array increasing and if we use the array_pop() function, then it will decrease the array length by one.
Pushing key and value in Associative Array
There is no array_push() equivalent for associative arrays because there is no way to determine the next key. We can use the array_push() method, but adding the index starts from 0 and 1 and not the keys we desire. So if you want to push key and value, then you can do the following code.
<?php $data = ['name' => 'Krunal', 'education' => 'BE']; $data['age'] = 26; $data['business'] = 'IT'; print_r($data);
Array ( [name] => Krunal [education] => BE [age] => 26 [business] => IT )
In the output, you can see that, and we can add multiple keys of your choice and not the ones that numeric keys php provides by default.
Pushing a value into the array automatically creates a numeric key for it. Therefore, when inserting a key-value pair to the array, you already have the key, and you don’t need one to be created for you. That key is the numeric key, which starts from 0.
Adding element at the start of the Array
To add an element at the start of the array, you can use the PHP array_unshift() function. It appends the item at the beginning of the array at the index of 0.
You can see that our new element “PHP” is added at the index position 0.
The array_unshift() function adds new elements to the array. The new array values will be inserted at the beginning of the array. You can insert one value or as many as you like. Numeric keys will start at 0 and increase by 1 every time a new element is added. String keys will remain the same.
Finally, PHP array_push() function example is over.