How to generate unique random numbers in PHP

How to generate unique random numbers in PHP

Whether it is a web application, a WAP or a mobile application, random numbers have their place. In several small projects that I have been exposed to recently, I often need to deal with random numbers or random arrays. Therefore, I will summarize some common methods for how to generate non-repeating random numbers in PHP (ps: Methods 1, 4, and 5 are my Commonly used ones, the rest are collected from the Internet)

Method 1:

//shuffle 将数组顺序随即打乱  shuffle ($numbers); //array_slice 取该数组中的某一段  $num=6; 
$result = array_slice($numbers,0,$num); 
print_r($result); 
?>

Method 2:

//播下随机数发生器种子，可有可无，测试后对结果没有影响 srand ((float)microtime()*1000000); 
shuffle ($numbers); //跳过list第一个值（保存的是索引） while (list(, $number) = each ($numbers)) { echo "$number "; 
} 
?>

Method 3:

function NoRand($begin=0,$end=20,$limit=5){ 
$rand_array=range($begin,$end); 
shuffle($rand_array);//调用现成的数组随机排列函数  return array_slice($rand_array,0,$limit);//截取前$limit个  } 
print_r(NoRand()); 
?>

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

Method 4:

array(); while(count($tmp)<5){ 
$tmp[]=mt_rand(1,20); 
$tmp=array_unique($tmp); 
} 
print_r($tmp);
?>

Method 5:

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

The above introduces how to generate non-repeating random numbers in PHP, including the relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.