How to generate non-repeating random numbers in php

How to generate non-repeating random numbers in php: first use the range function to create an array containing elements in a specified range; then use the shuffle function to rearrange the elements in the array in random order; finally take out a section of the array element.

Implementation principle:

Shuffle the order of the array and then take a certain segment of the array.

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The method is as follows:

Method one:

The range() function creates an array containing a specified range of elements.

shuffle() function rearranges the elements in the array in random order.

<?php 
//range 是将1到100 列成一个数组 
$numbers = range (1,100); 
//shuffle 将数组顺序随即打乱 
shuffle ($numbers); 
//array_slice 取该数组中的某一段 
$result = array_slice($numbers,0,3); 
print_r($result); 
?>

Method 2:

<?php 
$numbers = range (1,20); 
srand ((float)microtime()*1000000); 
shuffle ($numbers); 
while (list (, $number) = each ($numbers)) { 
echo "$number "; 
} 
?>

Method 3:

Use PHP to randomly generate 5 non-repeating values ​​between 1-20

<?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()); 
?>

Or if you don’t shuffle

<?php 
$tmp=array(); 
while(count($tmp)<5){ 
$tmp[]=mt_rand(1,20); 
$tmp=array_unique($tmp); 
} 
print join(&#39;,&#39;,$tmp); 
?>

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