CODEWITHSUNDEEP
phprandom
user3141230
user3141230

Reputation: 35

Generate Random Number based on a Condition?

Is it possible to generate a random number based on a condition?

I would like to generate a random number, 1-1000. However, I do not want the same random value to generate any number that is already present within my variables

<?php
    $low= 0;
    $height= 1000;
    $num_1 =1;
    $num_2 =3;
    $num_3 =4;
    $num_4 =6;
    $num_5 =2;

    $num = rand($low, $height) & != ($num_1 - $num_5) ;
?>

Upvotes: 0

Views: 1865

Answers (3)

xvidun
xvidun

Reputation: 477

From what I understand I think you are implying that you need UNIQUE random numbers to variables.

Although for your case of five numbers you can use the solution provided above, yet the solution does not gurantee smooth running (what if the rand function were to return the same number indefinitely, though practically least possible for large numbers).

ALGORITHM:

low = 0
height = 1000

val = array(1,2,3,4,5,....1000)// better not to waste cycles generating them

i=0

while(i<5)
{
t = rand(low , height);
num[i] = val[t];
val[t] = val[height];   
i++;
height--;
}

Upvotes: 1

GrahamTheDev
GrahamTheDev

Reputation: 24825

$low= 0;
$height= 1000;
$numbers = array(1, 3, 4, 6, 2);

$num = rand($low, $height);

while (in_array($num, $numbers)) {
    $num = rand($low, $height);
}

I am assuming that adding your 'not allowed' values to an array would be more efficient?

Upvotes: 1

Chizzle
Chizzle

Reputation: 1715

Bear with this long conditional:

$num = rand($low, $height);
while($num == $num_1 || $num == $num_2 || $num == $num_3 || $num == $num_4 || $num == $num_5){
    $num = rand($low, $height);
}

Upvotes: 0

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