How to enter the length of an array in php

In PHP, array is a very important data type that can store multiple values ​​and can be accessed through index.

When we use an array, sometimes we need to know the length of the array, that is, how many elements there are in the array. In PHP, there are many ways to get the length of an array, and this article will introduce you to several of them.

Method 1: count() function

The count() function is one of PHP's built-in functions, used to get the number of elements in an array. The basic syntax of this function is as follows:

count(array $array, int $mode = COUNT_NORMAL): int

Among them, $array represents the array whose length is to be obtained, and $mode represents the calculation mode, which is optional. The default mode is COUNT_NORMAL, which means normal calculation. Another mode is COUNT_RECURSIVE, which means recursive calculation, that is, counting the number of all elements in a multidimensional array.

The following is an example code for using the count() function to obtain the length of an array:

<?php
  $arr = array("apple", "orange", "banana", "pear");
  $len = count($arr);
  echo "数组长度为：$len";
?>

The output result is:

数组长度为：4

Method 2: sizeof() function

## The #sizeof() function and the count() function have the same function and can be used to obtain the length of the array. The basic syntax is as follows:

sizeof(array $array, int $mode = COUNT_NORMAL): int

is similar to the count() function. $array represents the array to obtain the length, and $mode represents the calculation mode, which is optional. The default mode is COUNT_NORMAL, which means normal calculation. Another mode is COUNT_RECURSIVE, which means recursively counting the number of all elements in a multidimensional array.

The following is an example code for using the sizeof() function to obtain the length of an array:

<?php
  $arr = array("apple", "orange", "banana", "pear");
  $len = sizeof($arr);
  echo "数组长度为：$len";
?>

The output result is:

数组长度为：4

Method 3: Obtain the length by traversing the array

We can also loop through the array and count the number of elements in the array. The implementation of this method is relatively simple. You only need to use a for loop or foreach loop to traverse the array, and add one to the counter each time it loops.

The following is a sample code that uses a loop to traverse an array to obtain the length:

<?php
  $arr = array("apple", "orange", "banana", "pear");
  $len = 0;
  foreach($arr as $value){
    $len++;
  }
  echo "数组长度为：$len";
?>

The output result is:

数组长度为：4

Method 4: Use the end() function to obtain the length of the last element of the array The index value

end() function is used to point the internal pointer to the last element of the array and return the value of that element. If we use the end() function to get the index value of the last element of the array, then the index value plus one is the array length.

The following is an example code for using the end() function to obtain the length of an array:

<?php
  $arr = array("apple", "orange", "banana", "pear");
  end($arr);
  $len = key($arr) + 1;
  echo "数组长度为：$len";
?>

The output result is:

数组长度为：4

To sum up, the methods for obtaining the length of an array in PHP are: There are many ways, and we can choose the appropriate method according to the actual situation. In actual development, it is recommended to use the count() function or the sizeof() function because they are simple, clear, and easy to understand and maintain.

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