This article summarizes 5 methods for generating non-repeating random numbers. Among them, methods 1, 2, and 3 are my commonly used methods, and methods 4 and 5 come to Du Niang. There are still other methods, and everyone is welcome to tell us about the missing methods, so that we can make progress together
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 generating non-repeating random numbers in PHP.
Method one:
The code is as follows:
<?php $numbers = range (1,50); //shuffle 将数组顺序随即打乱 shuffle ($numbers); //array_slice 取该数组中的某一段 $num=6; $result = array_slice($numbers,0,$num); print_r($result); ?>
Method two:
The code is as follows:
<?php $numbers = range (1,20); //播下随机数发生器种子,可有可无,测试后对结果没有影响 srand ((float)microtime()*1000000); shuffle ($numbers); //跳过list第一个值(保存的是索引) while (list(, $number) = each ($numbers)) { echo "$number "; } ?>
Method three:
The code is as follows:
<?php function NoRand($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 numbers between 1-20 The value of
Method 4:
The code is as follows:
<?php $tmp=array(); while(count($tmp)<5){ $tmp[]=mt_rand(1,20); $tmp=array_unique($tmp); } print_r($tmp); ?>
Method 5:
The code is as follows:
<?php $tmp = range(1,30); print_r(array_rand($tmp,10)); ?>
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 array function. Most random numbers can be generated from the perspective of arrays. Of course, if you have a better method, please let us know. This article can be considered as an introduction.
The above is the detailed content of Summary of methods for generating non-repeating random numbers in php. For more information, please follow other related articles on the PHP Chinese website!