Setting Random Variables for a single day - How do I do this?

yorktown

I wanted to have a set of Random PHP variables that are set constant for a single day.

Example:


// TODAY's DATE
$todaysdate=date("Ymd");

// RANDOM VARIABLES
$a=rand(1,10);
$b=rand(101,110);
$c=rand(1001,1010);

echo "$a | $b | $c";

Under the normal rules for random variables, each visitor for a web page would receive a random set of numbers. So on April 19, by hitting refresh you may see the following

5 | 108 | 1002
1 | 109 | 1006
10 | 101 | 1004

etc etc...

I want the variable to be set for a single day, to change randomly the next day and be set for that day, and so on.

April 19, 2009 Results:

5 | 108 | 1002
5 | 108 | 1002
5 | 108 | 1002
each refresh page is consistent.

April 20, 2009 Results:

1 | 109 | 1006
1 | 109 | 1006
1 | 109 | 1006
each refresh page is consistent.

April 21, 2009 Results:

10 | 101 | 1004
10 | 101 | 1004
10 | 101 | 1004
each refresh page is consistent.

Now how do I do this? I don't want to use MySQL for this. I want to keep the processes simple and within PHP.

Thanks.

Weedpacket

Seed the random number generator with something that depends on the day.

yorktown

Tool? Which one? I don't understand.

Is there not a way to program this?

yorktown

Also - seeding the code so that it is dependent on a particular day is not exactly what I want.

Ex:

If the day is MONDAY then $a=2

or

If the day is the 1st then $a=2

etc

In such a case, on MONDAY the $a value will always be 2. This is not what I want. I want each day complete randomness, however, set for that day.

Weedpacket

yorktown wrote:
Tool? Which one? I don't understand.

If you mean how do you seed the random number generator, the [man]srand[/man] function cited on the [man]rand[/man] page does this.

I want each day complete randomness, however, set for that day.

Again, seed the random number generator with a known value. Each seed defines a whole sequence of pseudorandom numbers. Use the same seed, get the same sequence. Try it.

djjjozsi

save the random numbers into a database with the date, and generate a new one if the currend date isn't in the table.

bradgrafelman

djjjozsi;10911707 wrote:
save the random numbers into a database with the date, and generate a new one if the currend date isn't in the table.

But why involve the overhead of a database? The [man]srand/man can do just that with much less overhead, and it'd be a lot simpler too.