How to join an array in php

How to join an array in php

An array is a data type used to store a series of values ​​in PHP. PHP arrays can be ordered or unordered, and can contain values ​​of different types. Arrays are one of the most useful data structures in PHP when you need to store multiple pieces of data.

In PHP, the method of adding items to an array depends on the array type and the presence or absence of keys. Here are the different ways of adding array items in PHP:

1. Assignment Method Adding Array Items

In PHP, you can add items to a by using a key assignment in a keyed array. Suppose you have an associative array that assigns a key to each element and stores a range of values:

$colors = array("red" => "Apple", "green" => "Kiwi", "yellow" => "Banana");

Now if you want to add a key-value pair to the $colors array, you You can use the following code:

$colors["purple"] = "Grapes";

This will add a new key "purple" and value "Grapes" to the array$colors middle.

2. array_push() function adds array items

array_push() The function can add one or more values ​​to the end of the array. This function adds a value to the end of the array and returns the length of the new array. This function can be used with numerically indexed arrays and associative arrays.

For example, assuming you have a numerically indexed array $nums, you can use the array_push() function to add a new item to the end of the array:

$nums = array(1, 2, 3);
array_push($nums, 4, 5, 6);

At this time the array$nums will become (1, 2, 3, 4, 5, 6).

3. array_unshift() function adds array items

The opposite of the array_push() function is the array_unshift() function. This function adds one or more values ​​to the beginning of the array and returns the length of the new array.

For example, assuming you have a numerically indexed array $nums, you can use the array_unshift() function to add a new item to the beginning of the array:

$nums = array(4, 5, 6);
array_unshift($nums, 1, 2, 3);

At this time the array$nums will become (1, 2, 3, 4, 5, 6).

4. Adding a value to a string

In PHP, you can add a value to the end of a string by using the dot operator. For example:

$str = "Hello";
$str .= " world!";

At this time the variable $str will contain the string "Hello world!".

5. Add a value using a subscript to "[]" after the array

Add a value or key-value pair by using an index in square brackets after the array into the array. If the index does not exist, the new item will be added to the end of the value, if it exists, the old value will be overwritten.

For example:

$nums = array(1, 2, 3);
$nums[3] = 4;

At this time the array $nums will become (1, 2, 3, 4).

Summary

The above introduces several methods of adding array items in PHP, which are suitable for different types of arrays, including numeric index arrays and associative arrays. Mastering these methods gives you more flexibility in using PHP arrays to store and manipulate data.

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