Delete the first few digits in php array

In PHP, array is a very commonly used data type. It allows us to store multiple values ​​and access these values ​​through indexes. Sometimes, we need to remove the first few elements from an array so that only the following elements remain. This article will introduce the method and precautions for deleting the first digits of an array in PHP.

I. Basic syntax of PHP arrays

In PHP, arrays can be defined using the following syntax:

$array = array(value1, value2, ..., valueN);

Among them, value1, value2, ... , valueN is the value to be stored in the array. We can also define arrays in the form of key-value pairs:

$array = array(key1 => value1, key2 => value2, ..., keyN => valueN);

II. How to delete the first few digits of an array

In PHP, you can use array_slice() Function to delete the first few digits of an array. The syntax of this function is as follows:

array_slice(array, offset, length, preserve_keys)

Parameter description:

• array: Required parameter, the array of elements to be deleted.
• offset: Required parameter, specifying the position from which to delete elements. If it is a positive number, the calculation starts from the front of the array; if it is a negative number, it starts from the back of the array.
• length: Optional parameter, specifying the number of elements to be deleted. If not specified, all elements starting at offset and ending at the end of the array are deleted.
• preserve_keys: Optional parameter, if set to true, the key name of each element in the original array will be preserved. If set to false, the key names will be numbered again starting from 0.

Sample code:

$fruits = array('apple', 'banana', 'cherry', 'date', 'elderberry');
$fruits_slice = array_slice($fruits, 2);
print_r($fruits_slice);

Output result:

Array
(
    [0] => cherry
    [1] => date
    [2] => elderberry
)

In the above code, the array_slice() function starts from 2 Start by deleting the first two elements and return a new array $fruits_slice.

III. Notes

1. array_slice()The function returns a new array instead of modifying the original array. If you want to modify the original array, you can use the following syntax:

$array = array_splice($array, $offset, $length);

where $array is the array from which the elements are to be deleted, $offset and $length are respectively the starting position of deletion and the number of elements to be deleted.

2. When using the array_slice() function, note that the $offset parameter can be a negative number. If negative, calculation starts from the end. For example, if you want to delete the last two elements, you can write like this:

$array = array_slice($array, 0, -2);

3. If the length parameter of the array_slice() function is a negative number, Then the number of deleted elements is all elements starting from offset to the end of the array, except the last -length elements. For example, if you want to delete the last two elements, you can write like this:

$array = array_slice($array, 0, -2);

4. When using the array_splice() function, pay attention to the convenience when modifying the original array. You can also write comments for reading and post-maintenance.

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