php基本语法

print “hello world”

 <html>
  <head>
    <title>Leap Years</title>
  </head>
  <body>
    <?php
      echo "hello world";
      echo "hello" . " " . "haifei";// . 连接符
    ?>
  </body>
</html>

注释

// 单行注释
/* 多行注释 */

定义变量
php不区分类型，直接赋值

$name = "tony";
$age = 18;

数组
取值 [] 等同{}

$language = array("php", "java", "ruby","python");
echo $language[2];
echo $language{2};
$language{2} = "go";
echo $language[2];

$myAssocArray = array('year' => 2012,
                        'colour' => 'blue',
                        'doors' => 5);
echo $myAssocArray['colour'];//blue

if else

$value = 3;
if($value == 1){
    echo "value is one";
}else if($value == 2){
    echo "value is two";
}else{
    echo "echo else";
}

switch

//写法1
$var = 2;
switch($var){
    case 1:
        break;
    case 2:
        break;
    default:
        break;
}

//写法2
$var = 2;
switch($var):
    case 1:
        break;
    case 2:
        break;
    default:
        break;
endswitch;

for

for($leap = 2000; $leap<2050; $leap+=4){
    echo " $leap \n";
}

foreach

$arr = array("a","b","c");
foreach($arr as $a){
    echo $a;
}

while

$loopCount = 0;
while ($loopCount<4){
   echo "<p>Iteration number: {$loopCount}</p>";
   $loopCount ++;
}

while ($loopCount<4):
   echo "<p>Iteration number: {$loopCount}</p>";
   $loopCount ++;
endwhile;

do while

$i = 0;
do {
    echo $i;
} while ($i > 0);

功能函数

字符串操作

$name = "HaiFei";
print strlen("david");//长度
$sub = substr($name,0,3);//字符串截取
print $sub;
print strtoupper($name);//大写
print strtolower($name);//小写
print strpos($name, "a");//位置
if(strpos($name,"z") === false){//是恒等计算符   同时检查表达式的值与类型
print "sorry not found";
}

取整，四舍五入

$round = round(M_PI);
print $round;  // prints 3

// This time, round pi to 4 places
$round_decimal = round(M_PI, 4);
print $round_decimal; // prints 3.1416

随机数

// prints a number between 0 and 32767
print rand();
// prints a number between 1 and 10
print rand(1,10);

数组操作

$arr = array();
array_push($arr,"11");
array_push($arr,"22");
print count($arr);// 2

$array = array(5, 3, 7, 1);
sort($array);
print join(", ", $array);// prints "1, 3, 5, 7"
rsort($array);
print join(":", $array);// prints "7:5:3:1"

函数

function aboutMe($name, $age){
    echo "Hello! My name is $name, and I am $age years old";
}
aboutMe("haifei", 18);

类

 // The code below creates the class
 class Person {
     // Creating some properties (variables tied to an object)
     public $isAlive = true;
     public $firstname;
     public $lastname;
     public $age;

     // Assigning the values
     public function __construct($firstname, $lastname, $age) {
       $this->firstname = $firstname;
       $this->lastname = $lastname;
       $this->age = $age;
     }

     // Creating a method (function tied to an object)
     public function greet() {
       return "Hello, my name is " . $this->firstname . " " . $this->lastname . ". Nice to meet you! :-)";
     }
   }

 // Creating a new person called "boring 12345", who is 12345 years old ;-)
 $me = new Person('boring', '12345', 12345);

 // Printing out, what the greet method returns
 echo $me->greet(); 

class Person {
  public $isAlive = true;

  function __construct($name) {
      $this->name = $name;
  }

  public function dance() {
    return "I'm dancing!";
  }
}

$me = new Person("Shane");
if (is_a($me, "Person")) {
  echo "I'm a person, ";
}
if (property_exists($me, "name")) {
  echo "I have a name, ";
}
if (method_exists($me, "dance")) {
  echo "and I know how to dance!";
}

const , static关键字

class Ninja extends Person {
    const stealth = "MAXINUM";// 没有 $

    static public $job = "coder";
    static public function proclaim() {
        return "A kingly proclamation!";
    }

}

echo Ninja::stealth;
echo Ninja::$job;
echo Ninja::proclaim();

map

$myArray = array('name'=>'haifei',
            'age'=> 18,
            'address'=>"beijing");

foreach($myArray as $key=>$value){
    echo $key . ":" . $value . "\n";
}