Java基础——方法的可变参数-白红宇

Java基础——方法的可变参数

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发布时间：2019-06-29

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可变参数

解决参数个数不确定引起的问题。

可变参数的本质是一个数组，编码示例

public class ChangedMethod {	public static void main(String[] args) {		double[] pay=new double[]{1,2,3};				double sunPay1=getSun1(pay);		System.out.println("sunPay1:"+sunPay1);				double sunPay2=getSun2(pay);		System.out.println("sunPay2:"+sunPay2);				double sunPay3=getSun3(pay);		System.out.println("sunPay3:"+sunPay3);				double sunPay4=getSun4(2,pay);		System.out.println("sunPay4:"+sunPay4);			}	 static double getSun1(double[] arr) {		 double sum=0.0;		 for(double price:arr){			 sum += price;		 } 		return sum;	}	 	 //可变参数	 static double getSun2(double... arr) {		 double sum=0.0;		 for(double price:arr){			 sum += price;		 } 		return sum;	}	 	 static double getSun3(double[] arr) {		 double sum=0.0;		 for(int index = 0; index

可变参数的本质是一个数组，编码示例运行结果

sunPay1:6.0sunPay2:6.0sunPay3:6.0sunPay4:12.0

可变参数必须作为最后一个参数编码示例

public class ChangedMethod_02 {	public static void main(String[] args) {				double sun1=getSun1(1,2,3,4);		System.out.println("sun1:"+sun1);				double sun2=getSun2(1,2,3,4);		System.out.println("sun2:"+sun2);		        double[] pay=new double[]{1,2,3,4};		double sunPay1=getSun1(pay);   //不能用方法getSun2(double a, double... arr)		System.out.println("sunPay1:"+sunPay1);	}	 static double getSun1(double... arr) {		 double sum=0.0;		 for(double price:arr){			 sum += price;		 } 		return sum;	}	 	 static double getSun2(double a, double... arr) {		 double sum=0.0;		 for(double price:arr){			 sum += price;		 } 		return sum*a;	}	 	 }

可变参数必须作为最后一个参数编码示例程序运行结果