Network Programming

The math functions commonly used in the php tutorial The tanh () function returns the hyperbolic tangent. Syntax tanh (x) Parameter Description x Required. A few. Description Returns the hyperbolic tangent of x, defined as sinh (arg) / cosh (arg). * / echo tanh (-m_pi); / / output -0.996272076221 echo & quo ...

Php code <? Php // Method one: function extend_1 ($ file_name) {$ retval = ""; $ pt = strrpos ($ file_name, "....

^ s * | s * $ Comment: Can be used to delete the first line of the first line of the whitespace characters (including spaces, tabs, page breaks, etc. ), A very useful expression $ action = trim ($ _ get ['action']); if ($ action == "sub") {$ str = $ _post ['dir']; & ...

php tutorial to remove the timestamp on Monday and Sunday can take over the following two examples of the timestamp on Monday and Sunday can see a lot of things, to keep thinking Oh, the first custom time stamp out the specified date Better, but it's more practical to take out the second one on Monday and Sunday. * / function getmonsun () {$ curtime = time (); ...

Method 1 delete yourtable where [id] not in (select max ([id]) from yourtable group by (name + value) b on a.id = b.id where b.id ...

SQL take ABC field duplicate record a record of the maximum value of a field, select Max (a), b,c from table name GROUP by B,c file is very simple. About the Max Max () function The Max function returns the maximum value in a column. Null values are not included in the calculation. SQL Max () syntax select MAX (COLUMN_NAME) from table_name Note: Min and Max can also be used for text columns to get word ...

max () returns the maximum value. Syntax max (x, y) Parameter Description x Required. A few. y necessary. A few. Description max () Returns the value with the highest value in the argument. If there is only one parameter and an array, max () returns the largest value in the array. If the first argument is an integer, string, or floating point number, at least two arguments are required and max () returns the largest of these values. You can compare an unlimited number of values. echo max (1,3,5,6,7); & ...

Recently in the preparation of a library management program, you need to verify the correctness of the ISBN code of the book, check some information to understand the composition of the ISBN code of the book, the details can refer to: ISBN - Wikipedia, the following is a brief description of what ISBN code: International Standard Book Number (ISBN; is-ben), is an internationally accepted or independent publication (except for regularly published journals). Publishers can be clear by ISBN ...

PHP pseudo-static use is mainly to hide the passed parameter name. Today we introduce to you a total of four pseudo-static PHP method, I hope we can further deepen the understanding of PHP pseudo-static through these four methods. The following is the full method code: [pre] <? Php // pseudo static method a // localhost/php100/test.php?id|1@action|2 $ Php2Html_Fi ...

Php tutorial simple Chinese word segmentation system structure: the first hash table, trie index tree node Advantages: word segmentation, do not need to predict the length of the query, along the tree chain verbatim match. Disadvantages: Construction and maintenance is more complex, word branches are more, wasting some space. * @version 0.1 * @todo Constructs a common dictionary algorithm and writes a simple word segmentation * @author shjuto@gmail.com * trie dictionary tree * * / class trie {& nb ...

I now need to remove the latest content from each category as follows: select * from test group by category_id order by `date` The result is as follows. This is not the data I want, because msyql has the order of execution is the order of reference write: select ... from ... where .... group by ... having ... order by .. Execution order: ...

Query SQL statement with date addition this is an SQL statement that adds the dates of the MSSQL access, which provides a large number of functions for the database tutorial date operation, and today we add the date by using the DateAdd function. *//method One stored procedure set NOCOUNT on DECLARE @kp table ([id] int,[ys] int,[syrq] datetime) Insert @kp Select 1, 2, ' 2 ...

// include.php file echo a (); / / result bb?> include.php file as follows <? php // create include.php for other file calls function a () / / Define function a {b (); ...

This article is mainly introduced str_replace function to replace a single character, and replace the data, and specify the number of str_replace replacement, the last replacement is very useful, especially in the SEO optimization methods. / mixed str_replace (mixed $ search, mixed $ replace, mixed $ subject [, int & $ count]) function returns a string or any problem in the search ...

To output PHP data to an excel spreadsheet, PHP has great support in this area, and PHP can output a simple excel form in just a few simple sentences. PHP Code: header ("Content-type: application / vnd.ms-excel"); header ("Content-Disposition: attachment; filename = users.xls & qu ...

php tutorial to determine whether the class exists function class_exists / / bool class_exists (string $ class_name [, bool $ autoload = true]) / / This function is defined class is defined check. this function checks whether or not the given class has been defined. // returns true if c ...

In the mysql tutorial on Chinese sort is a more interesting question, especially for the field is uft-8 or not gbk, gb2312 field type is Chinese sort out there is a problem, let's look at an example. create table `test111cnnet` (& nbsp; ...

SQL Date-time subtraction statement This tutorial takes advantage of the DateDiff function to subtract the dates of the database tutorials Oh, and here's how to subtract n from the MSSQL date. Two date subtraction 1 in SQL, Days of difference select trunc (sysdate, ' yyyy ')-to_date (' 2009-01-04 ', ' yyyy ') from dual; 2, the difference of the number of months select Months_b ...

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 ...

Php code <? Php // Method one: function extend_1 ($ file_name) {$ retval = ""; $ pt = strrpos ($ file_name, "....