Php If Numeric

In this lesson, we want to learn how to increase the intelligent processing capacity of the Web page. Basic functions Welcome to the third and final lesson of this tutorial. If you've learned the first and second lessons, you've mastered the basics of installing and programming MySQL and PHP. Here are some of the other functions of PHP that might be useful to you and make your development process simpler. 　　First, let's look at the document. You should know some basic concepts of the header file, right? The header file is an external file whose contents are included in the main program. ...

An array is a collection of data that organizes a series of data to form an operational whole. Each entity in the array contains two keys and values. First, what is the array Array is a collection of data, a series of data organized together to form an operational whole. Each entity in the array contains two keys and values. Second, the statement data There are two main ways to declare an array in PHP: First, the array () function declaration array, one is directly assigned to the array element. Fei Fei Asp! Technology Paradise <1> array () function ...

PHP is a great language for the fast-growing dynamic web pages. PHP also has the characteristics of junior programmers friendly, such as PHP do not need dynamic statement. However, these features may cause a programmer to unintentionally sneak a security vulnerability into a web application. There are a number of proven vulnerabilities in popular security mailing lists in PHP applications, but once you understand the basic types of vulnerabilities that are common in PHP applications, you'll find it equally as secure as any other language. In this article, I will detail in detail what will lead to security vulnerabilities ...

Array definition and initialization What is an array? An array is a programming structure that is a variable that holds a set of values ​​or a series of values. For example, at the time of the census, personal identity registration, such as name, gender, nationality, birth, etc. can be used as an array. The array created in the php tutorial is defined using the array () structure, such as $ people = array ('name', 'sex', 'nation', 'brith'); and how to display the value of each element in the array Is to use the index from 0, the index number ...

mysql tutorial _result (): The advantage is easy to use; The disadvantage is that the function is less, a call can only get a row of elements of the result data set, a relatively low efficiency for larger database tutorials; mysql_result () function returns a field in the result set value. If successful, the function returns the field value. If it fails, it returns false. Syntax mysql_result (data, row, field) Parameter Description data Required. Specifies the result identifier to use. This identifier is ...

In PHP, you can judge numbers, characters, objects, arrays, and so on, including those functions such as see Is_bool (), Is_int (), Is_integer (), Is_float (), Is_real (), Is_object (), and Is_array (). I don't know how much you know. --//double-precision is_double is_double-is_float () alias Description This function is an alias function of Is_float (). &n ...

As PHP programmers, especially novices, always know too little about the dangers of the Internet, for many of the external invasion are at a loss what to do, they do not know how hackers invaded, submitted to the invasion, upload vulnerabilities, sql Injection, cross-scripting and more. As a basic precaution you need to be aware of your external commits and do a good job with the first side of the security mechanism to handle the firewall. Rule 1: Never trust external data or enter information about Web application security, the first thing you must recognize is that you should not trust external data. External data (outside d ...

Operation database is the basis of dynamic Web programming, this article gives you a detailed description of how PHP operates MySQL database 1. Establish and close connection 1 mysql_connect () resource mysql_connect ([string hostname [:p ort][:/path/to/socket][,string username] [, String Passwor ...

PHP cookies Use the detailed tutorial 1, set cookies PHP with the Setcookie function to set cookies. It is important to note that cookies are part of the HTTP protocol header and are used to pass information between browsers and servers, so you must call the cookie function before any content output that belongs to the HTML file itself. The Setcookie function defines a cookie and attaches it to the back of the HTTP header, the prototype of the Setcookie function is as follows: int Set ...

The characters you need to escape in the PHP tutorial regular expressions are as follows: $^* () +={}[]|/:<>. "Note: Perl style expressions require/start and end, such as:/food/table matching characters Food Perl modifiers are as follows: I complete a case-insensitive search G Find all occurrences (all occurrences, complete global search) m treats a string as multiline (m means multiple (listbox)). By default, ^ and $ ...