第2章：关键字

完整关键字列表（50 个）

Java 有 50 个关键字，按类别分组：

访问控制

• public, private, protected

类、方法和变量修饰符

• abstract, class, extends, final, implements, interface, native, new, static, strictfp, synchronized, transient, volatile

程序控制

• break, case, continue, default, do, else, for, if, instanceof, return, switch, while

错误处理

• assert, catch, finally, throw, throws, try

包相关

• import, package

基本类型

• boolean, byte, char, double, float, int, long, short

变量引用

• super, this, void

未使用

• const, goto

关键字示例

// 访问控制
public class MyClass {
    private int value;
    protected String name;
    
    // 方法修饰符
    public static void main(String[] args) {
        final int x = 10;
        
        // 控制流
        if (x > 5) {
            for (int i = 0; i < 10; i++) {
                if (i == 5) break;
                continue;
            }
        }
        
        // 异常处理
        try {
            throw new Exception();
        } catch (Exception e) {
            // handle
        } finally {
            // cleanup
        }
    }
}

关键字分类总结

1. 访问控制：public, private, protected
2. 类相关：class, interface, extends, implements, abstract, final, static
3. 控制流：if, else, for, while, do, switch, case, break, continue
4. 异常：try, catch, finally, throw, throws
5. 基本类型：int, long, float, double, char, byte, short, boolean, void