PHP快速入门(1)
PHP快速入门(1)——基本语法,控制结构和简单的面向对象
本文提供的所有程序已在PHP5下经过测试 。转载请注明出处。
# 快速开始
<?php
echo "<p>Hello World </p>";
?>
echo "<p>Hello World </p>";
?>
# 注释
<?php
// 介是单行注释
/* 介是多行注释... */
echo "<p>This is something about php </p>";
?>
// 介是单行注释
/* 介是多行注释... */
echo "<p>This is something about php </p>";
?>
# 链接字符串
<?php
$str1 = "You will see: ";
$str2 = "How to concat strings.";
echo "<p>".$str1.$str2."</p>";
?>
$str1 = "You will see: ";
$str2 = "How to concat strings.";
echo "<p>".$str1.$str2."</p>";
?>
# 条件判断
<?php
$flag = true;
if($flag)
{
echo "<p>Under the condition...</p>";
}
else
{
echo "<p>Under other conditions...</p>";
}
$val = 100;
if($val == 0)
{
echo "<p>It is zero.</p>";
}
elseif($val < 0)
{
echo "<p>It is a negative.</p>";
}
else
{
echo "<p>It is a positive.</p>";
}
?>
$flag = true;
if($flag)
{
echo "<p>Under the condition...</p>";
}
else
{
echo "<p>Under other conditions...</p>";
}
$val = 100;
if($val == 0)
{
echo "<p>It is zero.</p>";
}
elseif($val < 0)
{
echo "<p>It is a negative.</p>";
}
else
{
echo "<p>It is a positive.</p>";
}
?>
# 分支结构
<?php
$case = 10;
$result = "";
switch($case)
{
case 1:
$result = "In case one.";
break;
case 2:
$result = "In case two.";
break;
case 3:
$result = "In case three.";
break;
default:
$result = "In other case.";
break;
}
echo "<p>".$result."</p>";
?>
$case = 10;
$result = "";
switch($case)
{
case 1:
$result = "In case one.";
break;
case 2:
$result = "In case two.";
break;
case 3:
$result = "In case three.";
break;
default:
$result = "In other case.";
break;
}
echo "<p>".$result."</p>";
?>
# 三元运算
<?php
$val = 1;
$exp = ($val == 0) ? "<p>The value is zero</p>" : "<p>The value is not zero</p>";
echo $exp;
?>
$val = 1;
$exp = ($val == 0) ? "<p>The value is zero</p>" : "<p>The value is not zero</p>";
echo $exp;
?>
# 数组array
<?php
echo "<ul>";
$arr1 = array("John", "Jane", "Julie");
echo "<li>People in array #1: $arr1[0], $arr1[1], $arr1[2]</li>";
$arr2 = array(0 => "Jodan", 1 => "Jack", 2 => "James");
echo "<li>People in array #2: $arr2[0], $arr2[1], $arr2[2]</li>";
$arr3 = array(1 => "Tom", "Sam", "Kim");
echo "<li>People in array #3: $arr3[1], $arr3[2], $arr3[3]</li>";
$arr4[3] = "Avril";
$arr4[2] = "Taylor";
$arr4[1] = "Miley";
echo "<li>People in array #4: $arr4[1], $arr4[2], $arr4[3]</li>";
echo "</ul>";
?>
echo "<ul>";
$arr1 = array("John", "Jane", "Julie");
echo "<li>People in array #1: $arr1[0], $arr1[1], $arr1[2]</li>";
$arr2 = array(0 => "Jodan", 1 => "Jack", 2 => "James");
echo "<li>People in array #2: $arr2[0], $arr2[1], $arr2[2]</li>";
$arr3 = array(1 => "Tom", "Sam", "Kim");
echo "<li>People in array #3: $arr3[1], $arr3[2], $arr3[3]</li>";
$arr4[3] = "Avril";
$arr4[2] = "Taylor";
$arr4[1] = "Miley";
echo "<li>People in array #4: $arr4[1], $arr4[2], $arr4[3]</li>";
echo "</ul>";
?>
# for循环和foreach
<?php
$fib[0] = 1;
$fib[1] = 1;
for($i = 2; $i < 10; $i++)
{
$fib[$i] = $fib[$i-1] + $fib[$i-2];
}
echo "<p>The Fibonacci: ";
foreach($fib as $index => $value)
{
echo (string)$value." ";
}
echo "</p>";
?>
$fib[0] = 1;
$fib[1] = 1;
for($i = 2; $i < 10; $i++)
{
$fib[$i] = $fib[$i-1] + $fib[$i-2];
}
echo "<p>The Fibonacci: ";
foreach($fib as $index => $value)
{
echo (string)$value." ";
}
echo "</p>";
?>
# while循环
<?php
$n = 6;
$c = 1;
$r = 1;
while($c <= $n)
{
$r *= $c;
$c += 1;
}
echo "<p>$n != $r </p>";
?>
$n = 6;
$c = 1;
$r = 1;
while($c <= $n)
{
$r *= $c;
$c += 1;
}
echo "<p>$n != $r </p>";
?>
# 函数和递归
<?php
function factorial($val)
{
if($val == 0) return 1;
return $val * factorial($val - 1);
}
$n = 7;
echo "<p>$n! = ".(string)factorial($n)."</p>";
?>
function factorial($val)
{
if($val == 0) return 1;
return $val * factorial($val - 1);
}
$n = 7;
echo "<p>$n! = ".(string)factorial($n)."</p>";
?>
# 简单的面向对象
<?php
class User
{
// fields
private $name;
private $email;
private $status;
// constructor
function User($name, $email)
{
$this->name = $name;
$this->email = $email;
$this->status = "";
}
// getters
function getName() { return $this->name; }
function getEmail() { return $this->email; }
function getStatus() { return $this->status; }
// setters
function setStatus($value) { $this->status = $value; }
// methods
function SignOut()
{
echo "User $this->name signed out.";
}
}
$u = new User("John", "johnsmith@gmail.com");
$u->setStatus("online");
echo "<p>";
echo "Name: ".$u->getName()."<br />";
echo "Email: ".$u->getEmail()."<br />";
echo "Status: ".$u->getStatus()."<br />";
echo "</p>";
echo "<p>".$u->SignOut()."</p>";
?>
class User
{
// fields
private $name;
private $email;
private $status;
// constructor
function User($name, $email)
{
$this->name = $name;
$this->email = $email;
$this->status = "";
}
// getters
function getName() { return $this->name; }
function getEmail() { return $this->email; }
function getStatus() { return $this->status; }
// setters
function setStatus($value) { $this->status = $value; }
// methods
function SignOut()
{
echo "User $this->name signed out.";
}
}
$u = new User("John", "johnsmith@gmail.com");
$u->setStatus("online");
echo "<p>";
echo "Name: ".$u->getName()."<br />";
echo "Email: ".$u->getEmail()."<br />";
echo "Status: ".$u->getStatus()."<br />";
echo "</p>";
echo "<p>".$u->SignOut()."</p>";
?>
# 更简单的Getter和Setter
<?php
class Rectangle
{
// fields
private $offsetX;
private $offsetY;
private $width;
private $height;
// constructor & destructor
function __construct($x, $y)
{
$this->offsetX = $x;
$this->offsetY = $y;
}
function __destruct()
{
unset($this->offsetX);
unset($this->offsetY);
unset($this->width);
unset($this->height);
}
// getters
function __get($property)
{
if(isset($this->$property)) { return($this->$property); }
else return(NULL);
}
// setters
function __set($property, $value) { $this->$property = $value; }
// methods
function GetArea()
{
return $this->width * $this->height;
}
}
$rect = new Rectangle(10, 20);
$rect->width = 48;
$rect->height = 72;
echo "<p>";
echo "Offset X: ".$rect->offsetX."<br />";
echo "Offset Y: ".$rect->offsetY."<br />";
echo "Width: ".$rect->width."<br />";
echo "Height: ".$rect->height."<br />";
echo "Area: ".$rect->GetArea();
echo "</p>";
?>
class Rectangle
{
// fields
private $offsetX;
private $offsetY;
private $width;
private $height;
// constructor & destructor
function __construct($x, $y)
{
$this->offsetX = $x;
$this->offsetY = $y;
}
function __destruct()
{
unset($this->offsetX);
unset($this->offsetY);
unset($this->width);
unset($this->height);
}
// getters
function __get($property)
{
if(isset($this->$property)) { return($this->$property); }
else return(NULL);
}
// setters
function __set($property, $value) { $this->$property = $value; }
// methods
function GetArea()
{
return $this->width * $this->height;
}
}
$rect = new Rectangle(10, 20);
$rect->width = 48;
$rect->height = 72;
echo "<p>";
echo "Offset X: ".$rect->offsetX."<br />";
echo "Offset Y: ".$rect->offsetY."<br />";
echo "Width: ".$rect->width."<br />";
echo "Height: ".$rect->height."<br />";
echo "Area: ".$rect->GetArea();
echo "</p>";
?>
posted on 2010-10-19 13:32 John Smith 阅读(3070) 评论(3) 编辑 收藏 举报