suanshi.java

一个四则运算计算器

package edu.bupt.calculate.example;

//产生随机的四则运算题目,输入答案,判断正误   
import java.util.*;

class suanshi {
	// 产生随机数//
	Random rand = new Random();

	// int a=(int)Math.random()*50;
	// int b=(int)Math.random()*20;//这样的数每次运行时都是一样的.
	// int c=(int)Math.random()*10+1;
	// rand.setSeed(long d);
	int a = (int) rand.nextInt() / 1000000;

	int b = (int) rand.nextInt() / 1000000;

	int c = (int) (rand.nextFloat() * 10 + 1);

	public static double sum = 0;// 一定要声明为static的,否则后面的SUM就会为0

	public suanshi() {
	}

	char d;

	public suanshi(int k) { // 产生运算符号//
		if (1 <= c && c <= 3) {
			d = '+';
			sum = a + b;
		} else if (4 <= c && c <= 6) {
			d = '-';
			sum = a - b;
		} else if (7 <= c && c <= 8) {
			d = '×';
			sum = a * b;
		} else {
			d = '÷';
			sum = a / b;
		}
		System.out.print("(" + a + ")" + "  " + d + "  " + "(" + b + ")" + "=");

	}
}