10 recommended courses on loop creation

The difficulty in random generation is how to avoid collisions. Some people say to use mechanisms such as md5 and GUID. Of course you can, but as an account, it looks messy, and the number of generated digits is too long. This method only needs to solve concurrent collisions within 1 second, because the fixed head uses unixtime time, which is accurate to the second. If it exceeds 1 second, the time of this head must have changed. At the same time, this method can also generate random order numbers for users. The test condition is to use a loop to create 10,000 random accounts (millisecond level), with 0 collisions, and 100,000 accounts with approximately 0-3 collisions. There should be no Internet company that would create so many accounts at the same time in an instant, so it is enough to handle a scale of billions of PV. ~~~.java // Automatically generate random user names // Test, create 10,000 random accounts in a loop, 0 collisions, 100,000 about 0-3 collisions, enough to cope with billions of PVs in the future private function genUserNumber() { $chars = "01234567

1. PHP random username account generation

Introduction: The difficulty in random generation is how to avoid collisions. Some people say to use mechanisms such as md5 and GUID. Of course it is possible, but as an account, it looks messy, and the number of generated digits is too long. It only needs to solve concurrent collisions within 1 second, because the fixed header uses unixtime time, which is accurate to the second. If it exceeds 1 second, the time of this header will definitely change. At the same time, this method can also generate random order numbers for the user. . The test condition is to use a loop to create 10,000 random accounts (millisecond level), with 0 collisions. There should be 0-3 collisions in 100,000. No Internet company will...

2. Generation of random username accounts in PHP

##Introduction: Difficulties in random generation It depends on how to avoid collisions. Some people say that it is possible to use mechanisms such as md5 and GUID, but as an account, it looks messy, and the number of generated digits is too long. This method only needs to solve concurrent collisions within 1 second. , because the fixed header uses unixtime time, which is accurate to seconds. If it exceeds 1 second, the time of this header must have changed. At the same time, this method can also generate random order numbers by the user. The test condition is to use a loop to create 10,000 random order numbers. Account (millisecond level), 0 collisions, there are about 0-3 collisions in 100,000. There should be no Internet company...

3. Am I really? The Nothing Lyrics php loop detects whether the directory exists and creates the loop to create the directory

Introduction: Do I Really Have Nothing Lyrics: Do I Really Have Nothing Lyrics php loop detects whether the directory exists And create a loop to create a directory: This method of looping to create a directory will generate the image.gif directory. The copy code is as follows: $filepath = "test/upload/2010/image.gif"; mk_dir($filepath); // Loop to create a directory function mk_dir ($dir, $mode = 0755) { if (is_dir($dir) || @mkdir($dir,$mode)) return true; if

4. Example of creating a multi-level directory in a php loop

Introduction: Example of creating a multi-level directory in a php loop

5. php loop Detect whether the directory exists and create it (create the directory in a loop)_PHP tutorial

Introduction: PHP loops to detect whether the directory exists and creates it (create the directory in a loop). This method of creating a directory in a loop will generate the image.gif directory. The copy code is as follows: $filepath = "test/upload/2010/image.gif"; mk_dir($filepath); // Create a directory in a loop function mk_di

6. php loop creation directory example sharing (php creates multi-level directory)_PHP tutorial

Introduction: php loop creation directory example sharing ( php creates multi-level directories). Copy the code as follows: function mk_dir($dir, $mod = 0777) { if(!is_dir($dir) || mkdir($dir, $mod)) { if(!mk_dir(dirname($dir, $mod)) )) { return false; } } return mkdir($dir, $mo

7. php loop creation directory example sharing_PHP tutorial

Introduction: PHP loop creation directory example sharing. This article mainly introduces the example of creating a directory in PHP loop. The principle is to continuously try to create the upper directory, and so on. Friends in need can refer to the following code: function mk_dir($d

8. php loop to create directory_PHP tutorial

Introduction: php loop to create directory. The code is taken from thinkphp: function mk_dir($dir, $mod = 0777 ) { if(!is_dir($dir) || mkdir($dir, $mod)) { if(!mk_dir(dirname($dir, $mod))) { return false; } } return mkdir($dir, $ mo

9. discuz Please tell me

Introduction: discuz Please tell me how to write a for loop to create a discuz group Script, but the interface is a bit hard to understand. Could you please tell me directly how to simulate it------Solution-------------------- PHP code