Java 流程控制及方法实践

1.计算器

package JavaMethod;

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import java.util.Scanner;

public class CalculatorEvo {
    public static void main(String[] args) throws ScriptException {
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine se = manager.getEngineByName("js");
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入计算式");
        while (scanner.hasNext()){
            String sc = scanner.nextLine();
            if (sc.equals("exit")){
                break;
            }
            
            //强制转换为Double时，当结果为整数类型则报错
            Number result = (Number)se.eval(sc);  
            System.out.println("结果是"+result);
            System.out.println("请输入计算式,或输入exit退出");
        }
        System.out.println("感谢您的使用");
        scanner.close();
    }
}

package JavaMethod;

im