52 lines
740 B
Markdown
52 lines
740 B
Markdown
# 条件判断与循环
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## 学习目标
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- 掌握 if-elif-else 条件判断
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- 学会使用 for 循环
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- 掌握 while 循环
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## 条件判断
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```python
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age = 18
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if age < 18:
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print("未成年人")
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elif age < 60:
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print("成年人")
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else:
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print("老年人")
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```
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## for 循环
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```python
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# 遍历列表
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fruits = ["apple", "banana", "cherry"]
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for fruit in fruits:
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print(fruit)
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# 使用 range
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for i in range(5):
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print(i) # 输出 0, 1, 2, 3, 4
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```
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## while 循环
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```python
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count = 0
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while count < 5:
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print(count)
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count += 1
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```
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## 循环控制
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- `break` - 跳出循环
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- `continue` - 跳过当前迭代
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## 动手练习
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1. 编写程序判断奇偶数
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2. 使用循环打印乘法表
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3. 计算 1 到 100 的和
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