PHP Summary of Methods for Generating Non repeating Random Numbers

Whether it is Web application, WAP or mobile application, random numbers have their applications. In the recent contact with several small projects, I often need to deal with random numbers or random arrays, so for PHP how to generate non-repeating random numbers, several commonly used methods are summarized in 1.

Method 1:

<?php 

$numbers = range (1,50); 

//shuffle  Scramble the array order immediately  

shuffle ($numbers); 

//array_slice  Fetches a certain in the array 1 Segment  

$num=6; 

$result = array_slice($numbers,0,$num); 

print_r($result); 

?>

Method 2:

<?php 

$numbers = range (1,20); 

// Sow the seeds of random number generator, optional, and have no effect on the results after testing 

srand ((float)microtime()*1000000); 

shuffle ($numbers); 

// Skip list No. 1 1 Values (the index is saved) 

while (list(, $number) = each ($numbers)) { 

echo "$number "; 

} 

?>

Method 3:

<?php 

function NoRand($begin=0,$end=20,$limit=5){ 

$rand_array=range($begin,$end); 

shuffle($rand_array);// Call the ready-made array random arrangement function  

return array_slice($rand_array,0,$limit);// Before interception $limit A  

} 

print_r(NoRand()); 

?>

The above can randomly generate 5 non-repeating values between 1 and 20

Method 4:

<?php 

$tmp=array(); 

while(count($tmp)<5){ 

$tmp[]=mt_rand(1,20); 

$tmp=array_unique($tmp); 

} 

print_r($tmp);

?>

Method 5:

<?php 

$tmp = range(1,30);

print_r(array_rand($tmp,10));

?>

This may be simpler than it is called (ps: If you specify a step size in range, you must pay attention to whether the second parameter of array_rand exceeds the length of $tmp).

PHP provides a very rich array function, and most of the random numbers can be generated from the perspective of arrays. Of course, if you have a better method, please tell me. This article is also a good example.