The previous article "talk about PHP syntax" has talked about PHP Data Types and expressions. Now let's take a look at the variables and constants of PHP.
Let's take a look at this example first.
File: test. php
<? PHP
// This is a single line Comment Method
# This is another single line Comment Method
/* This is a multiline comment method.
Let's take a look at the example below */
Funtion display ($ file, $ line)
{
Global $ message;
Echo "file: $ file <br> ";
Echo "line: $ line <br> ";
Echo "message: $ message <br> ";
}
$ Message = "this is a routine. ";
Display (_ file _, _ line _);
?>
The result is as follows:
Text. php
15
This is a routine
In the preceding example, function is a custom function. The following two variables $ file and $ line are two local variables. They only play a role in the function body and do not interfere with the variation amount of the function in vitro, if $ file or $ line exists in the function body, the values of both $ file and $ line may not be the same. _ File _ and _ line _ are two constants. Their limit values have been fixed. _ File _ is the object name, And _ line _ is the row number of the execution line. In the function body, there is also a global $ message, which is used to enable the fully qualified variable $ message to function body, this sentence can also be written as $ global ["message"];
For information generated by get, post, and cookie mechanisms, PHP automatically treats it as a PHP variable. In this way, the information processing of the submitted form is extremely easy. As follows:
File: form.html
<HTML> <Body>
<Form action = "deal. php">
Username: <input type = "text" name = "uname" size = 20> <br>
<Input type = "Submit" value = "OK">
</Form>
</Body>
File: Deal. php
<? PHP
Echo "your username is: $ uname ";
?>
the preceding Program requires the user to enter a user name. after submitting the form, return to the user name for confirmation. It can be seen that the uname in the form has become the $ uname variable in the deal. php program. Simple. :-)
let's take a look at the basic process control of PHP:
if... Else... Elseif
Syntax 1:
If (condition) {
statement body
}< br> syntax 2:
If (condition) {
statement body 1
}else {
statement body 2
}< br> syntax 3:
If (condition 1) {
statement body 1
} elseif (condition 2) {
statement body 2
}else {
statement body 3
}< br> we set the preceding deal. change the PHP program to:
if ($ uname = "James") {
echo "nice to meet you, James. ";
}elseif ($ uname =" Xiaohua ") {
echo" oh, it's Xiaohua. ";
}else {
echo" you are $ uname, right? ";
}< BR >?>
in addition to the IF statement, there is a while loop. Its syntax is as follows:
while (condition) {
statement body
}< br> when the condition is true, the statement body is executed.
do... The syntax of while is as follows:
do {
statement body
}while (condition)
execute the statement body once. If the condition is true, the statement body is executed cyclically.
the syntax of the For Loop is the same as that of C:
for (initial condition; judgment condition; condition change) {statement}
the break jumps out of the execution loop, and the continue interrupts the loop.
okay. Here is the article. I believe you will soon be able to get started with the above basics.
-- (to be continued) --
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