PHP: Method to generate non-repeating random numbers, PHP repeating random number method_PHP tutorial

PHP: Method of generating non-repeating random numbers, php repeating random number method

Source: http://www.ido321.com/1217.html

Whether it is a web application, a WAP or a mobile application, random numbers have their place. In several small projects I have recently come into contact with, 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:

<span><?php 
$numbers = range (1,50); 
<span>//shuffle 将数组顺序随即打乱 </span>
shuffle ($numbers); 
<span>//array_slice 取该数组中的某一段 </span>
$num=6; 
$result = array_slice($numbers,0,$num); 
print_r($result); 
?></span>

Method 2:

<span><?php 
$numbers = range (1,20); 
<span>//播下随机数发生器种子，可有可无，测试后对结果没有影响</span>
srand ((<span>float</span>)microtime()*1000000); 
shuffle ($numbers); 
<span>//跳过list第一个值（保存的是索引）</span>
<span>while</span> (<span>list</span>(, $number) = each ($numbers)) { 
<span>echo</span> <span>"$number "</span>; 
} 
?></span>

Method 3:

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

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

Method 4:

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

Method 5:

<span><?php 
$tmp = range(1,30);
print_r(array_rand($tmp,10));
?></span>

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).

PHP provides a very rich set of array functions. Most random numbers can be generated from the perspective of arrays. If you have any other methods, please feel free to provide them. The article will be continuously updated.

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