How to generate random numbers in php? (code example)

In PHP, you can use the built-in functions rand() and mt_rand() to randomly generate a number. Below we will introduce how these two built-in functions of PHP generate random numbers. We hope it will be helpful to everyone.

rand() function

rand() function can be specified to generate random numbers within a certain range integer and returns this random number.

Basic syntax:

rand(min,max)

• min: Specifies the minimum value that will be returned.

• #max: Specifies the maximum value that will be returned.

Note:

If min and max are specified in the rand() function, random numbers will be generated in the range of [min, max]; if not specified min and max, the random number will be generated in the range [0, getrandmax()].

The return value of the getrandmax() function is: the maximum upper limit (maximum possible value) that the rand() function can return.

Example:

<?php  
// 生成随机数
$Num1 = rand(); 
//输出
print_r("rand()： ".$Num1); 
print_r("<br><br>"); 
//在一个范围内生成随机数
$Num2 = rand(20,100); 
//输出
print_r("rand(20,100)： ".$Num2); 
?>

Output result:

##mt_rand() function

The mt_rand() function is based on the Mersenne Twister algorithm and can quickly generate a random integer.

Basic syntax:

mt_rand($min，$max)

Parameter description:

$min: Optional parameter, specifies the minimum number to be returned, the default value is 0.

$max: optional parameter. It specifies the maximum number to return.

When $min and $max exist, return a random integer between [min, max]; if $min and $max do not exist, return a random integer between [0, maximum possible value] . Example:

<?php  
// 生成随机数
$Num1 = mt_rand(); 
//输出
print_r("mt_rand()： ".$Num1); 
print_r("<br><br>"); 

//在一个范围内生成随机数
$Num2 = mt_rand(20,100); 
//输出
print_r("mt_rand(20,100)： ".$Num2); 
?>

Output:

Explanation: mt_rand() function can generate better random values; and it is the same as rand( ) function, it generates faster.

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