PHP Using rand to pick between specific numbers - php

Question

I know that rand(1,10); would generate a random number between 1 and 30.
How would I go about writing code that would pick a random number out of a group of numbers say 1,7,8 and 9?
Is it possible?
I am pretty sure rand is set up to only generate numbers within a range?

Answer 1

First thing is that rand(1,10) will generate a number between1 to 10 not 1 to 30.
PHP RAND FUNCTION
From a group of numbers, you can generate like this
$numbers = [1,7,8,9];
echo $numbers[rand(0,3)]

Answer 2

You can create custom array which you required, shuffle and get first value
$temp = [1,7,8,9];
shuffle($temp);
echo $temp[0];
shuffle — Shuffle an array
Demo

Answer 3

You could put your group of numbers into an array, and then use array_rand or shuffle to select one of them. For example:
$nums = array(1, 7, 8, 9);
$key = array_rand($nums);
echo $nums[$key] . PHP_EOL;
shuffle($nums);
echo $nums[0] . PHP_EOL;
Demo on 3v4l.org

Answer 4

Use this function (or inline code)
function SelectElementByRandom ( $list )
{
return count($list) ? $list[ rand(0,count($list)-1) ] : NULL;
}
The ?: operator ensures an result (NULL), even if the list is empty.
And for your example:
$result = SelectElementByRandom(array(1,7,8,9));

Answer 5

I would approach it like this. Create a loop that fills an array with random numbers in the range you're looking for (your group of numbers). After that, you choose a random index in that array, which is a random number in your group of numbers.
$min = 0;
$max = 10;
$group_size = 5;
$rand_group = array();
for($i = 0; $i < $group_size; $i++) {
$rand_group[$i] = rand($min,$max);
}
echo $rand_group[rand($min,$max)];