29 lines
747 B
Markdown
29 lines
747 B
Markdown
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1. `cout`: 用于标准输出，可以使用`<<`操作符将数据输出到屏幕上。
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```cpp
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std::cout << "Hello, world!" << std::endl;
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```
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2. `cin`: 用于标准输入，可以使用`>>`操作符从用户输入中读取数据。
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```cpp
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int num;
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std::cin >> num;
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```
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3. `endl`: 输出换行符并刷新输出缓冲区。
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```cpp
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std::cout << "Hello" << std::endl;
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```
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4. `cerr`: 用于输出错误信息，通常用于标准错误流。
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```cpp
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std::cerr << "Error: something went wrong!" << std::endl;
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```
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5. `fixed`和`setprecision`: 用于控制浮点数的输出精度。
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```cpp
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double num = 3.14159;
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std::cout << std::fixed << std::setprecision(2) << num << std::endl;
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```
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