关于命令行输入星号 * 当乘号做乘法运算出现异常的解释

星号*在命令行当乘号做乘法运算出现异常的解释

package chapter7;
//示例来自Java教材
public class Calculator {
	public static void main(String[] args) {
		if (args.length != 3) {
			System.out.println("Usage: java calculator operand1 operator operand2");
			System.exit(-1);
		}

		int result = 0;

		switch (args[1].charAt(0)) {
		case '+':
			result = Integer.parseInt(args[0]) + Integer.parseInt(args[2]);
			break;
		case '-':
			result = Integer.parseInt(args[0]) - Integer.parseInt(args[2]);
			break;
		case '.':
			result = Integer.parseInt(args[0]) * Integer.parseInt(args[2]);
			break;
		case '/':
			result = Integer.parseInt(args[0]) / Integer.parseInt(args[2]);
			break;
		}

		System.out.println(args[0] + " " + args[1] + " " + args[2] + "=" + result);
	}
}