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PHP array learning returns the last key name of the associative array
PHP array learning returns the last key name of the associative array
In the previous article, we learned how to return the key name of the first element of the array. If you are interested, you can click on the link to read → "PHP Array Learning: Extracting the key name key of the first element of the associated array》. This time we continue to talk about the key names of the array and introduce the method of returning the last key name of the array. If you need it, you can learn more~
→Related recommendations: 《PHP A large summary of the array learning series (continuously updated~) 》
The previous article introduced you to 3 methods of obtaining the first key name of an array. Today, this article also introduces 3 methods of returning an array. Let’s take a look at the last key name method!
Method 1: Use the array_key_last() function
array_key_last ($array)The function of the function is to: get the specified The last key name of array $array. If the specified array is an empty array, null is returned.
Let’s take a look at the implementation code:
<?php
header("content-type:text/html;charset=utf-8");
$array = ['a' => 1, 'b' => 2, 'c' => 3];
$lastKey = array_key_last($array);
echo "数组最后一个键名为：".$lastKey;
?>The output result is:
数组最后一个键名为：c
Method 2: Use end() key() function
First use the end($array) function to point the internal pointer of the array to the last element (at this time the last element is the current element of the array); then use key ($array) The function can get the key name of the current element.
Let’s take a look at the implementation code:
<?php
header("content-type:text/html;charset=utf-8");
$array = ['a' => 1, 'b' => 2, 'c' => 3];
end($array);
$lastKey = key($array);
echo "数组最后一个键名为：".$lastKey;
?>The output result is:
Method 3: Using array_keys () Function
array_keys() function can return a new array containing all the key names in the array; then the last element of this key name array is the last key name of the original array.
Let’s take a look at the implementation code:
<?php
header("content-type:text/html;charset=utf-8");
$array = ['a' => 1, 'b' => 2, 'c' => 3];
$keys=array_keys($array);
$lastKey = end($keys);
echo "数组最后一个键名为：".$lastKey;
?>The output result is:
Description: end() The function can point the internal pointer of the array to the last element of the array and return the value of the last element, or return FALSE if the array is empty.
In addition to using the end() function to obtain the last element of the array, you can also use the array_pop() function. For details, please refer to "PHP Array Learning: Obtaining the First/Last Element (1) 》.
If you want to randomly obtain the key name, you can use the array_rand() function, which can randomly select one or more elements from the array and return the key name. [Recommended reading article "PHP Array Learning: Randomly Obtaining Multiple Elements"]
That's all. If you want to know anything else, you can click this. → →php video tutorial
Finally, I would like to recommend a free video tutorial on PHP arrays: PHP function array array function video explanation, come and learn!
The above is the detailed content of PHP array learning returns the last key name of the associative array. For more information, please follow other related articles on the PHP Chinese website!
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