php gets how many items there are in an array

PHP is a scripting language widely used in web development. In PHP development, array is a very commonly used data type. Arrays can be used to store multiple values ​​conveniently, and to operate and process these values ​​conveniently.

In PHP, getting the number of elements in an array (that is, the length of the array) is a common operation. Two methods of obtaining the length of an array will be introduced below.

1. Use the count() function to obtain the length of the array

PHP’s built-in count() function can be used to obtain the length of the array. The method of using this function is as follows:

<?php
$fruits = array("apple", "banana", "orange");
$count = count($fruits);
echo $count;
?>

The above code will output the number "3", indicating that the array $fruits contains 3 elements. The count() function can accept an array as a parameter and return the number of elements in the array. If the argument is not an array, 0 is returned.

If you need to count the number of elements in a multi-dimensional array, the count() function is also applicable. For example, for the following multi-dimensional array:

<?php
$student = array(
    "name" => "Tom",
    "age" => 18,
    "scores" => array(80, 90, 85)
);
?>

To get the number of elements in the $scores subarray, you can use the following code:

<?php
$count = count($student["scores"]);
echo $count;
?>

The above code will output the number "3", which means $ The scores subarray contains 3 elements.

2. Use the sizeof() function to obtain the length of the array

In addition to the count() function, PHP also provides a sizeof() function for obtaining the length of the array. Both have the same function, but the function names are different. The method of using the sizeof() function to obtain the length of an array is almost the same as using the count() function. For example:

<?php
$fruits = array("apple", "banana", "orange");
$size = sizeof($fruits);
echo $size;
?>

The above code will also output the number "3", indicating that the array $fruits contains 3 elements. In addition, the sizeof() function can accept an optional second parameter to specify the type of return value. For example:

<?php
$fruits = array("apple", "banana", "orange");
$size = sizeof($fruits,1);
print_r($size);
?>

The above code will output the following content:

Array
(
    [0] => apple
    [1] => banana
    [2] => orange
)

Since the second parameter is specified as 1, the sizeof() function returns an associative array containing the array key name and value.

Summary

In PHP development, obtaining the length of an array is a very basic operation. This article introduces two methods: using the count() function and the sizeof() function. The results of both methods are the same, but the function names are different. In actual development, you can choose to use it according to your personal preferences. If you need to obtain the length of a multi-dimensional array, the method introduced above is also applicable.

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