PHP快速入门-基础语法及面向对象 php

配置sublime

{ "cmd": ["php", "$file"], "file_regex": "php$", "selector": "source.php" }

代码实例

基础语法

!=!==(值不同或类型不同) ?>=2"); } print "\n"; // 1<2// 循环类型// 有4种方式：for、while、do...while、foreach，前面3种和C语言中类似 for($i=1; $i<=3; $i++){ print($i); print "\n"; } // 1 2 3 $i = 1; while ($i<=3) { print $i; print " "; $i++; } print "\n"; // 1 2 3do{ print $i; print " "; $i--; } while($i>0); print "\n"; // 4 3 2 1// 遍历数组，指针移动 $list = array(1, 2, 3, 4, 5); foreach ($list as $value) { print "value = https://www.it610.com/article/$value"; } print "\n"; // value = https://www.it610.com/article/1 value = 2 value = 3 value = 4 value = 5 // 数组 3种 // 数字数组 $numbers = array(1, 2, 3, 4, 5); foreach ($numbers as $value) { print("$value "); } print "\n"; // 1 2 3 4 5// 修改数组元素 $numbers[0] = "one"; $numbers[1] = "two"; $numbers[2] = "three"; foreach ($numbers as $value) { print("$value "); } print "\n"; // one two three 4 5// 新建数组 $names[0] = 1; $names[2] = 2; foreach ($names as $value) { print("$value "); } print "\n"; // 1 2 // 获取数组长度 $length = count($numbers); for($i=0; $i<$length; $i++){ print($numbers[$i]); print(" "); } print "\n"; // one two three 4 5 // 关联数组 PHP 5.5.36，相当于python的字典 $people = ["Tom"=>"20", "Jack"=>"30", "Jimi"=>"40"]; // 访问数组元素 print($people["Tom"]); print(" "); print($people["Jack"]); print(" "); print($people["Jimi"]); print("\n"); // 20 30 40// 修改数组元素 $people["Tom"] = 50; $people["Jack"] = 60; $people["Jimi"] = 70; // 遍历数组元素 foreach ($people as $key => $value) { print("$key=>$value\n"); } print("\n"); // Tom=>50 // Jack=>60 // Jimi=>70// 多维数组 $cars = array( "first" => [ "name" => "car1", "color" => "white" ], "second" => [ "name" => "car2", "color" => "black" ]); // 访问多维数组元素 print($cars["first"]["name"]); # car1 print("\n"); // PHP数组排序函数 /* sort() - 对数组进行升序排列 rsort() - 对数组进行降序排列 asort() - 根据关联数组的值，对数组进行升序排列 ksort() - 根据关联数组的键，对数组进行升序排列 arsort() - 根据关联数组的值，对数组进行降序排列 krsort() - 根据关联数组的键，对数组进行降序排列 */// 字符串 // 双引号串中的内容可以被解释而且替换 // 单引号串中的内容总被认为是普通字符// 字符串并置运算符(.)：把两个变量连接在一起 $a = "hello"; $b = "world"; print($a . " " . $b); // hello world print("\n"); // 计算字符串的长度 $c = "中国"; print(strlen($a)); // 5 print(strlen($c)); // 6// 查找字符串 print(strpos($a, "ll")); // 2 print(strpos($a, "xx")); // FALSE print("\n"); // 函数 // $a普通参数， &$b引用参数， $c默认参数 function func_args($a, &$b, $c=2){ $a += 1; $b += 1; $c += 1; print("a=$a b=$b c=$c\n"); // a=2 b=2 c=3 return $a; // 返回值 }$args_a = 1; $args_b = 1; $ret = func_args($args_a, $args_b); print("ret=$ret\n"); // ret=2print("args_a=$args_a args_b=$args_b\n"); // args_a=1 args_b=2 ?>

面向对象

name . "\n"); print("protected age: " . $this->age . "\n"); print("private address: " . $this->address . "\n"); }final function work(){ print("龙生龙，凤生凤，老鼠生儿会打洞\n"); } }// 子类继承父类 class Child extends Father{ protected $age = 20; // 重写父类的protected属性function print_info(){ print("public name: " . $this->name . "\n"); print("protected age: " . $this->age . "\n"); // print("private address: " . $this->address . "\n"); // Undefined property }// function work(){ //print("子类不要父类的工作\n"); // } // Cannot override final method }$father = new Father(); $father->print_info(); /* public name: Tom protected age: 40 private address: 北京 */$child = new Child(); $child->print_info(); /* public name: Tom protected age: 20 */// 构造函数和析构函数class People{ function __construct($name){ $this->name = $name; print("父类构造函数 " . $this->name); }function __destruct(){ print("父类析构函数"); } }class Human extends People{ function __construct($name){ parent::__construct($name); // 调用父类的构造方法 print("子类构造函数 " . $this->name); } }$people = new People("老王"); print("\n"); /* 父类构造函数老王父类析构函数 */$human = new Human("小王"); print("\n"); // 父类构造函数小王子类构造函数小王父类析构函数// 接口 // 指定某个类必须实现哪些方法，但不需要定义这些方法的具体内容 // 接口中定义的所有方法都必须是公有，这是接口的特性 // 类可以实现多个接口interface ISleep{ public function sleep($time); }interface IEat{ public function eat(); }// 实现多接口 class Dog implements ISleep, IEat{ public function sleep($time){ print("sleep... time: $time\n"); } public function eat(){ print("eating ...\n"); } }$dog = new Dog(); $dog->sleep(5); $dog->eat(); /* sleep... time: 5 eating ... */// 抽象类// 任何一个类，如果它里面至少有一个方法是被声明为抽象的，那么这个类就必须被声明为抽象的。 // 定义为抽象的类不能被实例化。 // 继承一个抽象类的时候，子类必须定义父类中的所有抽象方法abstract class AbsBase{// 抽象方法 abstract public function sleep(); // 普通方法 public function eat(){ print("eat...\n"); }}class Cat extends AbsBase{ public function sleep(){ print("cat sleep...\n"); } }class Pig extends AbsBase{ public function sleep(){ print("pig sleep...\n"); } }// $abs = new AbsBase(); // Cannot instantiate abstract class$cat = new Cat(); $cat->eat(); // eat... $cat->sleep(); // cat sleep...$pig = new Pig(); $pig->eat(); // eat... $pig->sleep(); // pig sleep...// 静态属性 static // 不实例化类而直接访问class Foo{ public static $name = "static name"; public function get_name(){ print(self::$name); // 用一个变量来动态调用类的静态属性 print("\n"); } }print(Foo::$name); // static name// 通过类直接调用静态属性$foo = new Foo(); $foo->get_name(); // static name?>