How to remove index subscript from php array

When writing PHP programs, arrays and objects are often used, and elements in arrays and objects are often accessed using indexes. By default, the key values ​​of these elements will have subscripts, which can be a bit cumbersome to access. Therefore, sometimes we need to remove these subscripts to facilitate the writing and use of programs.

1. Why remove index subscripts

In PHP, elements in arrays and objects can be accessed using subscripts. The subscript can be a number or a string. For example, an ordinary array may look like this:

$fruits = array('apple', 'banana', 'orange');

The elements in this array are subscripted, and the subscripts are sequentially increasing numbers. Because these subscripts are critical to the running of the program, they cannot be removed by default.

However, in some cases, we don't care about the subscripts of the elements, but only need to access the values ​​of these elements. In this case, the subscript of the element will become a burden, increasing the complexity of the code and making it difficult to read. Therefore, we need to remove these subscripts to facilitate the writing and use of programs.

2. How to remove index subscripts

In PHP, there are many ways to remove index subscripts from elements in arrays or objects. Below we introduce these methods respectively.

1. Use the array_values() function

The array_values() function can rearrange the elements in the array in order and return a new array. The indexes of elements in this new array will start from 0 and increase sequentially. You can use this function to remove subscripts from an array.

For example, the following array:

$fruits = array('apple', 'banana', 'orange');

You can use the array_values() function to remove the key name:

$new_fruits = array_values($fruits);

In this way, the $new_fruits array only contains element values, not Contains the key names in the original array.

2. Use the json_decode() function

json_decode() function can convert a JSON format string into a PHP array or object. During this conversion process, the element's subscript will be automatically removed.

For example, the following JSON string:

$json_str = '["apple", "banana", "orange"]';

You can use the json_decode() function to convert it into an array:

$fruits = json_decode($json_str);

In this way, the elements in the $fruits array It only contains the value, without the subscript.

3. Use the object_to_array() function

If you need to convert an object into an array without retaining the subscript of the element, you can use the following function:

function object_to_array($obj) {
$arr = is_object($obj) ? get_object_vars($obj) : $obj;
if (is_array($arr)) {
    return array_map(__FUNCTION__, $arr);
}
else {
    return $arr;
}
}

To convert an object into an array without subscripts, you can use the following code:

$arr = object_to_array($obj);

In this way, the $arr array only contains the value of the element without any subscripts.

3. Precautions when using to remove index subscripts

Removing subscripts from arrays or objects will make the program code simpler and clearer, but it will also cause Take some risks. The following are some things to note:

1. The order of the elements is not guaranteed

After using the array_values() function or json_decode() function to remove the subscripts, the order of the elements may be changed. . Therefore, before using these functions, it is best to confirm whether the order of elements matters.

2. There may be duplicate key values

After using the array_values() function or json_decode() function to remove the subscripts, the subscripts of the elements will increase from 0. If there were duplicate elements in the original array, they will also become duplicates in the new array.

3. It may affect the readability of the code

In some cases, removing the subscript of the element may cause the readability of the code to decrease. For example, when using multi-dimensional arrays, the subscripts of elements can reflect the hierarchical relationship of the array structure. If you remove the subscripts of elements, this hierarchical relationship may become less clear. Therefore, it is better to retain the element's subscript when it is necessary to maintain the readability of the code.

4. Conclusion

Removing subscripts from arrays or objects can make the program simpler, but it also brings some risks. When using the method of removing subscripts, you need to pay attention to the above issues and weigh the pros and cons according to the actual situation.

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