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This article focuses on "what are the common methods of merging arrays in PHP". Interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn what are the common ways to merge arrays in PHP.

Array_merge () function-overrides array elements with the same key name

In PHP, we can merge arrays through the array_merge () function, that is, merge elements from multiple arrays into one array. The basic syntax format of the array_merge function is as follows:

Array_merge (array1,array2,array3...)

It is important to note that the parameter array123 is the array used for merging. Through this function, you can merge multiple arrays, where if two elements or multiple elements have the same key name, their key name is the last element after the merge will overwrite other elements.

Through this function can also merge an array, yes, an array how to say merge, this time is said if the function input only one array, and the key name of the array is an integer, when the function "merge" after the output of the new array its key name is re-indexed from 0.

Next, let's take a simple look at the use of the array_merge function through an example, as shown below:

Output result:

In the above example, both arrays to be merged have elements with the key name "b". You can see that the last element with the key name "b" in the final output, "yellow", overrides the previous element, so there are only three elements in the final output.

Let's take another look at the operation of "merging" an array. The example is as follows:

Output result:

In the above example, in an array that needs to be "merged", the key name of the array is an integer and is not indexed from 0, and when merged by the array_merge function, the key name of the array changes to index from 0.

Array_merge_recursive function-does not overwrite array elements with the same key name

In PHP, not only can the array_merge function combine arrays, what you need to know is that the array_merge_recursive function can also combine one or more numbers into an array. There is not much difference between the two. The difference you need to know is:

When there are elements with the same key name in two arrays that need to be merged, the two functions are handled differently. As mentioned in the above example, after the array_merge function is merged, their key name is the last element will overwrite other elements; but the array_merge_recursive function can recursively the same key name elements into an array and will not overwrite it.

Let's look at the example above, which is as follows:

Output result:

Through the above example, you can see the difference between the two functions: it should be noted that the same two arrays, through different functions to merge, the output is different, through the array_merge function to merge, the same element key name will be covered, through the array_merge_recursive function to merge the elements, the key name will not be covered.

Also, if you "merge" an array through the array_merge_recursive function, the result, like the array_merge function, will be re-indexed starting at 0.

Examples are as follows:

Output result:

From the above example, you can see that the main difference between the array_merge_recursive function and the array_merge function is whether elements with the same key name are overwritten.

+ merge arrays-overwrite array elements with the same key name after them

Merging arrays through + can be said to be the simplest method of array merging. Let's take a look at the usage directly through examples, which are as follows:

Output result:

As you can see from the above example, the difference between merging arrays through + and merging arrays through the array_merge function is:

The array_merge function encounters different array elements with the same key name, and will be overwritten after merging, covering the previous array elements.

While + encounters different array elements with the same key name to merge, the merge will also be overwritten, but the overwritten element is the following array element.

Array_combine function-

At this point, I believe you have a deeper understanding of "what are the common methods of merging arrays in PHP?" you might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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