Use the PHP function 'array_merge' to merge multiple arrays into one array

Use the PHP function "array_merge" to merge multiple arrays into one array

In PHP development, sometimes we need to merge multiple arrays into one large array to process data more conveniently. In order to achieve this function, PHP provides a powerful function "array_merge".

The array_merge function is very simple to use. It accepts multiple arrays as parameters and merges them into a new array. The following is the basic syntax used by the function:

array_merge ( array $array1 [, array $... ] ) : array

In the above syntax, $array1 is a required parameter, indicating the An array to merge. Among them, $... is an optional parameter, indicating the second and subsequent other arrays to be merged.

Let's look at a specific example: Suppose we have two arrays, one containing fruit names and one containing vegetable names. We want to merge these two arrays into one large array so that we can perform data manipulation more easily.

$fruits = array('apple', 'banana', 'cherry');
$vegetables = array('carrot', 'broccoli', 'cabbage');

$combinedArray = array_merge($fruits, $vegetables);

print_r($combinedArray);

The above code will output:

Array
(

[0] => apple
[1] => banana
[2] => cherry
[3] => carrot
[4] => broccoli
[5] => cabbage

)

As you can see, the two arrays were successfully merged into one in the new array. In the merged array, the elements of the fruit array are at the front and the elements of the vegetable array are at the back.

It should be noted that if the keys in the array are strings, then "array_merge" will produce some special effects when merging. Specifically, in the merged array, if the two arrays have the same string key name, the element value in the latter array will overwrite the corresponding element value in the previous array. At the same time, if there are discontinuous integer keys in the merged array, these keys will be reset to consecutive integers.

Here is an example to demonstrate this feature:

$array1 = array('a' => 'apple', 'b' => 'banana');
$array2 = array('b' => 'broccoli', 'c' => 'carrot');

$combinedArray = array_merge($array1, $array2);

print_r($combinedArray);

The above code will output:

Array
(

[a] => apple
[b] => broccoli
[c] => carrot

)

In this example, since key 'b' in array $array2 is the same as key 'b' in $array1, the value of key 'b' in the merged array is overwritten as 'broccoli'.

By using the "array_merge" function, we can easily merge multiple arrays into one large array. This function is widely used in PHP development and can greatly save time and workload in writing code.

Summary:

Use the PHP function "array_merge" to merge multiple arrays into one large array. It accepts multiple arrays as arguments and merges them into a new array. If the merged arrays have the same key names, the element values ​​in the latter array will overwrite the corresponding element values ​​in the previous array. If there are non-consecutive integer keys in the merged array, the keys are reset to contiguous integers. In practical applications, using the "array_merge" function can greatly simplify the processing and operation of arrays.

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