My question is probably very easy to answer. But I can't figure it out.
<?php
$id1 = rand(1,4);
$id2 = rand(1,4);
$id3 = rand(1,4);
$id4 = rand(1,4);
?>
I have this. But this sometimes creates multiple 3's etc. But within my project this is something that can't happen. At the end the range will be between 1 and 100. But this is just to test how it could work. Can someone please help me?
Create a range of values you can pick from. Shuffle it and take the first N results.
$range = range(0, 100);
shuffle($range);
$n = 10;
$result = array_slice($range, 0 , $n);
What is the purpose of this?
But, maybe you can simply do this:
$ids = range(1, 10);
shuffle($ids);
var_dump($ids);
/*
* 1st Result:
*
* array (size=10)
* 0 => int 10
* 1 => int 2
* 2 => int 5
* 3 => int 7
* 4 => int 9
* 5 => int 1
* 6 => int 3
* 7 => int 6
* 8 => int 4
* 9 => int 8
*/
shuffle($ids);
var_dump($ids);
/*
* 2nd Result:
*
* array (size=10)
* 0 => int 5
* 1 => int 9
* 2 => int 6
* 3 => int 4
* 4 => int 2
* 5 => int 10
* 6 => int 3
* 7 => int 7
* 8 => int 8
* 9 => int 1
*
*/
Check this code:
$values=array(); #preparint storage for numbers
$found=0; #number of found numbers
while($found!=4): #script is looking for 4 numbers
$v=rand(1,4); #range of numbers (1-4)
if(!in_array($v,$values)): #if found number isn't in array
$values[]=$v; #add it
$found++; #and increment counter
endif;
endwhile;
foreach($values as $value):
echo '<p>'.$value.'</p>'; #echo found numbers
endforeach;
Script is prepared to find 4 random, unique numbers in range 1-4.
$temp = array() // global
$id1 = is_num_exists(rand(1,4));
$id2 = is_num_exists(rand(1,4));
$id3 = is_num_exists(rand(1,4));
$id4 = is_num_exists(rand(1,4));
function is_num_exists($id){
while(in_array($id,$temp)){
$id = rand(1,4);
}
$temp[] = $id;
return $id
}
There are several approaches to achieve this:
Create an array of the given range (using the range() function) and shuffle it. To retrieve the values, you can walk it. This is useful if your range is not too large. That seems to be your case.
$range = range(1, 10);
shuffle($range);
If your range is much larger, you are better off storing your chosen values into a sorted array, checking each subsequent random number for being existent inside the array. That only goes for very large ranges, because not all possible values are loaded into memory, unlike the first example.
$passedValues = array();
for ($i = 0; $i < 10; $i++) {
$v;
do {
$v = rand(1, 100);
}
while (in_array($passedValues));
$passedValues[] = $v;
sort($passedValues);
}
The other answers provided some great code examples.
