PHP array random value, PHP array value_PHP tutorial

php array random value, php array value

array_rand() is quite useful when you want to take out one or more random cells from the 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 remove one or more cells from the array

mixed array_rand ( array input [, int num_req])

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.

If you only take out one, array_rand() returns the key name of a random cell, 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 such a website, and the banner changes randomly every time we refresh it. In this article, we will introduce to you how to use 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 random data is obtained, an image can be displayed.

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 an array:

$rn = array_rand($image);

Then let’s display a random image:

echo '<img src="'.$image[$rn].'">';

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 '<img src="'.$image[$rn].'">';

The above code is our code for randomly displaying pictures. If we want to add its own connection address to each picture, then we can slightly change the above code! Change the above array into a two-dimensional array:

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

The corresponding display code is:

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

Then we can complete the function of our title, randomly display images 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 '<a href="'.$image[$rn]['link'].'">';
echo '<img src="'.$image[$rn]['pic'].'">';

You can copy the above code to your web page and run it. Good luck

Original address: http://www.manongjc.com/article/833.html

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