[TOC] ***** # 5.1 一個簡單示例 ``` if car == 'bmw': print(car.upper()) ``` ## 5.2.5 檢查多個條件 **1. 使用and檢查多個條件** ``` age_0 >= 21 and age_1 >= 21 ``` **2. 使用or檢查多個條件** ``` age_0 >= 21 or age_1 >= 21 ``` ## 5.2.6 檢查特定值是否包含在列表中 ``` requested_toppings = ['mushrooms', 'onions', 'pineapple'] 'mushrooms' in requested_toppings #True ``` ## 5.2.7 檢查特定值是否不包含在列表中 ``` banned_users = ['andrew', 'carolina', 'david'] user = 'marie' if user not in banned_users: print(user.title() + ", you can post a response if you wish.") ``` ## 5.2.8 布爾表達式 game_active = True # 5.3 if 語句 ## 5.3.1 簡單的 if 語句 ``` if age >= 18: print("You are old enough to vote!") ``` ## 5.3.2 if-else 語句 ``` if age >= 18: print("You are old enough to vote!") print("Have you registered to vote yet?") else: print("Sorry, you are too young to vote.") print("Please register to vote as soon as you turn 18!") ``` ## 5.3.3 if-elif-else 結構 ``` if age < 4: price = 0 elif age < 18: price = 5 elif age < 65: price = 10 elif age >= 65: price = 5 ``` ## 5.3.4 使用多個 elif 代碼塊 可以在最后省略else ``` if age < 4: price = 0 elif age < 18: price = 5 elif age < 65: price = 10 elif age >= 65: price = 5 ``` ## 5.4.2 確定列表不是空的 ``` requested_toppings = [] #判斷列表是不是不為空 if requested_toppings: ```