switch中的变量声名和使用的问题解决方案

首先错误代码:

public static void main(String[] args) {
		int type = 2;
		switch (type) {
		case 0:
			int i = 0;
			System.out.println(type);
			break;
		case 1:
			int i = type;
			System.out.println(i);
			break;
		case 2:
			int i = type;
			System.out.println(i);
			break;
		case 3:
			int i = type;
			System.out.println(i);
			break;
		}
	}

 解决方法:

    使用java中的大括号来限定case中声明的变量的作用域

public static void main(String[] args) {
		int type = 2;
		switch (type) {
		case 0: {
			int i = 0;
			System.out.println(type);
			break;
		}
		case 1: {
			int i = type;
			System.out.println(i);
			break;
		}
		case 2: {
			int i = type;
			System.out.println(i);
			break;
		}
		case 3: {
			int i = type;
			System.out.println(i);
			break;
		}
		}
	}