Rand Php Example

First, get to know the random number function rand () provided by the PHP tutorial. The rand () function of PHP returns a random integer using the following rand (Min,max) optional argument min and Max can cause rand () to return a pseudo random integer between 0 and Rand_max. For example, want a random number between 5 and 15 (including 5 and 15), with Rand (5, 15). Let me take a look at a specific example, we do a basic function call, do not set the specific parameters, we get the random number ...

In our development of the efficiency has been a problem, especially for a lot of large data operations, today we ran into a random query data, at first we may think of the simplest order by RAND () to operate but the efficiency is not flattering ah. Recently, because of the need to study the MySQL random extraction implementation method. For example, to randomly extract a record from the TableName table, the general wording is: SELECT * from TableName ORDER by RAND () LIM ...

mt_rand () Returns a random integer using the mersenne twister algorithm. Syntax mt_rand (min, max) Description mt_rand () returns a pseudo-random number from 0 to rand_max if the optional parameters min and max are not provided. For example, want a random number between 5 and 15 (including 5 and 15), using mt_rand (5, 15). * / echo mt_rand (); & nb ...

Mt_rand and Rand function difference and example let's look at an example of the Mt_rand function. 　　function Roll () {return Mt_rand (1,6); echo Roll (); 　　function Roll ($sides) {return Mt_rand (1, $sides); echo Roll (6); Roll a six-s ...

In PHP to generate a CAPTCHA image is quite simple, because in PHP for us to provide a graphics Gd.dll library, to enable the GD graphics library we just php.ini in the PHP-GD front; Method a $authnum = '; $ychar = "0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z&qu ...

Php tutorial pattern verification code generation code and include ajax verification example application previously written verification code program is to provide the source code, but did not really figure verification code generated to verify the instance, this time we have a complete example of PHP validation It's There are 3 files: authcode.php ----- verification code generation php file authcode.html ----- front display page dealauthcode.php ----- ajax submitted to the background processing to determine the verification code is correct Processing page ...

Php tutorial pattern verification code generation code and include ajax verification example application previously written verification code program is to provide the source code, but did not really figure verification code generated to verify the instance, this time we have a complete example of PHP validation It's There are 3 files: authcode.php ----- verification code generation php file authcode.html ----- front display page dealauthcode.php ----- ajax submitted to the background processing to determine the verification code is correct Processing page ...

A simple interactive website example-Simple banner dynamic replacement (vi) 9. Simple banner dynamic replacement do not know if we have found the major sites on the banner of advertising banner, each time we visit these sites, will see a different advertising icon, or if you refresh the page every time, these ads banner will constantly change the random replacement. To achieve this effect although the use of JavaScript can also be achieved (like the Tenkine station of the dynamic transformation of advertising banner is by invoking JavaScript to achieve) ...

Recent learning URL jump when new into three PHP encryption and decryption function is very good, looks like the discuz ... Use these encryption to decrypt the reason is because sometimes their own URL address was acquired after you want to break inside the value of the content you must know your key, no key, he should be broken for a while to know the content of your URL. Pack them into a file called fun.php bar <?php function Passport_encrypt ...

Recently due to the need to study about MYSQL based random extraction method. For example, to randomly extract a record from the table table, we generally write: SELECT * FROM tablename ORDER BY RAND () LIMIT 1. However, I checked the official MYSQL manual, which prompts for RAND () probably means that the ORDER BY clause can not be used inside the RAND () function, because this will lead to multiple data columns were swept ...