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Generating A Random Number In PHP
By Amrit Hallan
Contributing Writer
Article Date: 2005-09-30
Sometimes you need to generate unique random numbers if you want to assign IDs to your members or assign unique values to your shopping cart items.
Here I'm just citing a reason whereas it depends on you for what purpose you'd like to generate a random number in your PHP scripts. I have written a small function that takes one argument. This argument tells the function how many digits you want in the generated number.
For a live example of the article, go to http://www.aboutwebdesigning.com/2005/09/29/generate-a-random-number-using-php
First, here's the function:
function random_num($n=5)
{
return rand(0, pow(10, $n));
}
If you send no argument to the random_num() function, it generates a 5-digit random number. This is how we use it:
<example>
echo random_num(); gave 96161 when tested and
echo random_num(7); gave 5983582 when tested
</example>
This function uses the PHP math function pow() to get the number of digits we want. The function pow() calculates the power of a number like say 10 raised to the power 5. In math we write it like 10 Exp 5. Basically, the real rand() function takes 2 arguments: the lower limit and the upper limit. So if you want to generate a random number that should be greater than 107 and less than 5067, you might get somethin like:
<example>
echo rand(107, 5067); gave 3456 when tested
</example>
Since we normally don't need the upper limits and the lower limits, I've elucidated a generic function that gives you a random number of spedicif number of digits.
About the Author:
Amrit Hallan is a freelance copywriter,
and a website content writer. He also writes
optimized content for better Search Engine
Ranking. To know more about his services,
visit his website site at
http://www.amrithallan.com/ah.asp?d=ar.
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