for.md

# for循环结构

正确的for循环结构是：

## 答案

D

## 选项

### A

```Java

for (int i = 0; i < 10; i++) {
    System.out.println("Hello World");
}
```

### B

```Java

String[] arr = new String[] {"1", "2", "3"};
for (String str : arr) {
    System.out.println("Hello World");
}
```

### C

```Java

Map<String, String> map = new HashMap<>();
for (String str : map.keySet()) {
    System.out.println("Hello World");
}
```

### D

以上都是