Java计算器程序

简化版计数器（数字的加减乘除）

package method;

import java.util.Scanner;

public class calc {
    public static int a = 0;
    public static int b = 0;
    public static String f = " ";
    public static String str1 = " ";

    public static void main(String[] args) {
        int t = 1;


        Scanner scanner = new Scanner(System.in); //输入初始化
        while (t == 1) {
            calc.str1 = scanner.next(); //输入
            char o = str1.charAt(0);
            if (o - '0' == 65) {
                System.out.println("结束");
                t = 0;

            } else if(str1.contains("+")) { //加法
                calc.f  = "\\+";
                calc3();
                int s = calc2('+',a,b);
                System.out.println(s);

            } else if(str1.contains("-")) { //减法
                calc.f  = "-";
                calc3();
                int s = calc2('-',a,b);
                System.out.println(s);

            } else if(str1.contains("/")) { //除法
                calc.f  = "/";
                calc3();
                int s = calc2('/', a, b);
                System.out.println(s);

            } else  if(str1.contains("*")) { //乘法
                calc.f = "\\*";
                calc3();
                int s = calc2('*', a, b);
                System.out.println(s);
            }
        }
        scanner.close();
        }
    public static void calc3() {
        String[] str2 = str1.split(f);
        calc.a = Integer.parseInt(str2[0]);
        calc.b = Integer.parseInt(str2[1]);
    }

    public static int calc2(char f, int a, int b) {

        switch (f) {
            case '+':
                return a + b;
            case '-':
                return a - b;
            case '*':
                return a * b;
            case '/':
                return a / b;
        }
        return 0;
    }
}

运行：

55+3（输入完毕敲回车）

58

可不断循环计算，输入q回车，则退出。