PHP array random value method and simple example

This article mainly introduces the method and simple examples of random values ​​​​in PHP arrays. Interested friends can refer to it. I hope it will be helpful to everyone.

array_rand() is useful when you want to remove one or more random cells from an array. It accepts input as an input array and an optional parameter num_req, which specifies how many cells you want to remove - if not specified, it defaults to 1.

array_rand -- Randomly take out one or more cells from the array

mixed array_rand ( array input [, int num_req])

array_rand() When you want to take out one or more cells from the array Very useful with multiple random units. It accepts input as an input array and an optional parameter num_req, which specifies how many cells you want to remove - if not specified, it defaults to 1.

If you only take out one, array_rand() returns the key name of a random unit, otherwise it returns an array containing the random key name. This way you can randomly pull out keys and values ​​from the array.

Don’t forget to call srand() to seed the random number generator.

Example 1. array_rand() Example

srand ((float) microtime() * 10000000); 
$input = array ("Neo", "Morpheus", "Trinity", "Cypher", "Tank"); 
$rand_keys = array_rand ($input, 2); 
print $input[$rand_keys[0]]."\n"; 
print $input[$rand_keys[1]]."\n";

We have visited this On the website, the banner changes randomly every time it is refreshed. In this article, we will introduce you to using PHP to implement this function.

Steps

The principle of program implementation is: call an array, each image corresponds to an element in the array, and then we set a random number. As long as a piece of data is randomly obtained, an image can be displayed. image.

The first step is for us to generate a random number. We get different random numbers every time we refresh. The specific code is:

srand((float) microtime() * 10000000);

After that, we set an array as image, and then set 5 array elements, the code is as follows:

$image[1]='/location/of/image1.jpg'; 
$image[2]='/location/of/image2.jpg'; 
$image[3]='/location/of/image3.jpg'; 
$image[4]='/location/of/image4.jpg'; 
$image[5]='/location/of/image5.jpg';

The following code implements the function of randomly selecting an element from the array:

$rn = array_rand($image);

Then let’s display a random picture:

echo &#39;<img src="&#39;.$image[$rn].&#39;">&#39;;

Just combine the above codes.

srand((float) microtime() * 10000000); 
$image[1]='/location/of/image1.jpg'; 
$image[2]='/location/of/image2.jpg'; 
$image[3]='/location/of/image3.jpg'; 
$image[4]='/location/of/image4.jpg'; 
$image[5]='/location/of/image5.jpg'; 
$rn = array_rand($image); 
echo &#39;<img src="&#39;.$image[$rn].&#39;">&#39;;

The above code is our code for randomly displaying pictures. If we want to add each picture to its own connection address, then we put the above code Just change it a little and you’re done! Change the above array to a two-dimensional array:

$image[1]['pic']='/location/of/image1.jpg'; 
$image[1]['link']='/location/of/link1.php';

The corresponding display code is:

echo &#39;<a href="&#39;.$image[$rn][&#39;link&#39;].&#39;">&#39;; 
echo &#39;<img src="&#39;.$image[$rn][&#39;pic&#39;].&#39;">&#39;;

Then we can complete the function of our title, randomly display pictures and connect to different specified addresses:

srand((float) microtime() * 10000000); 
$image[1]['pic']='/location/of/image1.jpg'; 
$image[1]['link']='/location/of/link1.php'; 
$image[2]['pic']='/location/of/image2.jpg'; 
$image[2]['link']='/location/of/link2.php'; 
$image[3]['pic']='/location/of/image3.jpg'; 
$image[3]['link']='/location/of/link3.php'; 
$image[4]['pic']='/location/of/image4.jpg'; 
$image[4]['link']='/location/of/link4.php'; 
$image[5]['pic']='/location/of/image5.jpg'; 
$image[5]['link']='/location/of/link5.php'; 
$rn = array_rand($image); 
echo &#39;<a href="&#39;.$image[$rn][&#39;link&#39;].&#39;">&#39;; 
echo &#39;<img src="&#39;.$image[$rn][&#39;pic&#39;].&#39;">&#39;;

Summary: The above is The entire content of this article is hoped to be helpful to everyone's study.

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