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This article mainly explains "how to add elements to the beginning and end of an array by 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 how PHP adds elements to the beginning and end of an array.

If you want to insert elements at the beginning and end of an array in PHP, you need to use the array_unshift function and the array_push function. Let's take a look at the use of these two functions respectively.

Array_unshift function-add elements at the beginning of the array

The built-in array_unshift function in PHP can insert new elements at the beginning of the array, which is similar to but different from array_shif. The basic syntax format of the array_unshift function is as follows:

Array_unshift (array,value1,value2,value3...)

Among them, it should be noted that:

The parameter array represents the array of elements that need to be inserted, and the parameter value123 represents the elements to be inserted into the array array. If the function runs successfully, the result returned is the number of elements in the array.

When we use the array_shif function to delete an element, we can delete only one element, but when we use the array_unshift function to add an element at the beginning of the array, we can add multiple elements. If the key name in the array is a number, it will still be reassigned from 0, and the key name string will not be affected.

Let's take a look at the use of the array_unshift function through an example, as follows:

Output result:

In the above example, we can see that when the program is finished, the result returned is the number of new elements in the array, and the new element key name starts at 0.

Let's take a look at the changes in the output of the elements with numeric key names in the original array, as shown in the following example:

Output result:

In the above example, an element is added through the array_unshift function, and if there is an element with a key name of a number in the array, the key name will be reassigned from 0 after the function runs.

Let's take a look at how to add elements to the end of an array.

Array_push function-add elements to the end of the array

If you can delete the element at the end of the array in PHP, you can add an element to the end of the array, and the array_push function can add an element to the end of the array. The basic syntax format of the array_push function is as follows:

Array_push (array,value1,value2...)

Among them, it should be noted that:

The parameter array represents the array of elements to be added, and the parameter value12 identifies the elements waiting to be added to the array array. The result of a successful run of the function is the number of elements in the new array.

Let's take a look at the use of the array_push function through an example, as follows:

Output result:

In the above example, you can add an element to the end of the array through the array_push function.

In the previous article, when you add an element at the beginning of an array through the array_unshift function, if the key name in the array is a number, the element key name in the array will be reassigned. Let's take a look at how the numeric key names of the elements in the array will affect the output when we run the array_push function to add the last element to the function. The example is as follows:

Output result:

As you can see in the above example, when you add an element at the end of an array through the array_push function, you do not reassign the key name to the element that has a numeric key name in the array.

At this point, I believe you have a deeper understanding of "how PHP adds elements to the beginning and end of an array". 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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