PHP generates non-repeating random number methods summarizing _php instances

Whether it's a Web application, a WAP, or a mobile app, random numbers have their way. I also often need to deal with random numbers or random arrays in several small projects that I have recently contacted, so there are a few ways to summarize how PHP produces non-repeating random numbers.

Method One:

Copy the Code code as follows:
<?php
s = range (1,50);
Shuffle the array order is scrambled
Shuffle (s);
Array_slice take a segment of the array
$num = 6;
$result = Array_slice (s, 0, $num);
Print_r ($result);
?>

Method Two:

Copy the Code code as follows:
<?php
s = range (1,20);
Sowing random number generator seeds, optional, no effect on the results after testing
Srand (float) microtime () *1000000);
Shuffle (s);
Skip list First value (save index)
while (list (,) = each (s)) {
echo "";
}
?>

Method Three:

Copy the Code code as follows:
<?php
function Norand ($begin =0, $end =20, $limit =5) {
$rand _array=range ($begin, $end);
Shuffle ($rand _array);//Call out-of-box array random permutation function
Return Array_slice ($rand _array,0, $limit);//$limit before intercept
}
Print_r (Norand ());
?>

The above can randomly produce 5 distinct values in 1-20.

Method Four:

Copy the Code code as follows:
<?php
$tmp =array ();
while (count ($tmp) <5) {
$tmp []=mt_rand (1,20);
$tmp =array_unique ($tmp);
}
Print_r ($TMP);
?>

Method Five:

Copy the Code code as follows:
<?php
$tmp = range (1,30);
Print_r (Array_rand ($tmp, 10));
?>

This may be simpler than the call. (PS: If you specify a step in range, you must be aware that the second parameter of Array_rand exceeds the length of $tmp).

PHP provides a very rich array of functions, the generation of random numbers can be mostly from the angle of the array, of course, if you have a better method, please also tell, this article is also a point of view.

