PHP | random_int() Function

The random_int () is an inbuilt function in PHP. The main function is to generate cryptographically secure pseudo-random integers value. When unbiased results occur in critical condition, then generated cryptographic random integers are used.
The different sources of randomness used in this function are given below :- 

• Window : CryptGenRandom() function used.
• Linux : getrandom(2) system call function to be used.

Syntax :  

int random_int ( $min, $max )

Parameter : 

• $min : Returned lowest value , Which is equal to PHP_INT_MIN or higher.
   
• $max : Returned highest value , which is less than or equal to PHP_INT_MAX.
   

Return Value :A cryptographically secure random integer in range min to max inclusive. 
Examples: 

Input : min= 10, max=10000
Output : int(5183)

Input : min= -244441, max= 1
Output : int(-60209)

Below programs illustrate the random_int() function in PHP. 
Program 1:

<?php
// PHP program to demonstrate
// the random_int() function 

// given min and max range
var_dump(random_int(1, 5555555));
var_dump(random_int(-1, 100000));
var_dump(random_int(9, 10));

?>

Output  

int(835427)
int(86695)
int(10)

Below programs illustrate the random_int() function in PHP.
Program 2: 
When write not valid range, then its comes runtime errors. 

<?php
// PHP program to demonstrate
// the random_int() function 

// given min and max range
// Not valid range
$t = (random_int(99, 11));

// Print result
echo "(int)", $t;
?>

Output  

Runtime Error

Exception Error :  

• invalid parameter givesTypeError.
• Invalid length of bytes givesError .
• If source of randomness is not found then Exception will be thrown.

References: 
https://www.php.net/manual/en/function.random-int.php