方法的调用 上机报告

定义一个Compute接口，有抽象方法add()，substract()，multiply()和divide()；定义一个实现Compute接口的类Computer，然后创建Computer对象完成加，减，乘和除四个方法的调用

Compute.java  

package com.csdn;

/**
 * 
 * @作者:Roc-xb
 * @联系QQ:327844761
 * @微信公众号：ewbang 定义一个Compute接口，有抽象方法add()，substract()，multiply()和divide()；
 */
public interface Compute {

	public double add(double n1, double n2);

	public double substract(double n1, double n2);

	public double multiply(double n1, double n2);

	public double divide(double n1, double n2);
}

ComputeImpl.java 

package com.csdn;
/**
 * 
 * @作者:Roc-xb
 * @联系QQ:327844761
 * @微信公众号：ewbang
 *
 */
public class ComputeImpl implements Compute {

	@Override
	public double add(double n1, double n2) {
		return n1 + n2;
	}

	@Override
	public double substract(double n1, double n2) {
		return n1 - n2;
	}

	@Override
	public double multiply(double n1, double n2) {
		return n1 * n2;
	}

	@Override
	public double divide(double n1, double n2) {
		if (n2 == 0) {
			throw new ArithmeticException("除数不能为0");
		}
		return n1 / n2;
	}

}

测试方法：

public static void main(String[] args) {
		ComputeImpl c = new ComputeImpl();
		int n1 = 10, n2 = 2;
		double add = c.add(n1, n2);
		double substract = c.substract(n1, n2);
		double multiply = c.multiply(n1, n2);
		double divide = c.divide(n1, n2);
		System.out.println(add);
		System.out.println(substract);
		System.out.println(multiply);
		System.out.println(divide);

	}

输出结果：