9.22 周五

// MethodOverload.java
// Using overloaded methods

public class MethodOverload {

public static void main(String[] args) {
System.out.println("The square of integer 7 is " + square(7));
System.out.println("\nThe square of double 7.5 is " + square(7.5));
}

public static int square(int x) {
return x * x;
}

public static double square(double y) {
return y * y;
}
}

运用了方法重载，，满足了，方法名相同，参数类型不同，参数个数不同，参数类型的顺序不同

返回值类型不同不可以作为方法重载的条件。

import java.math.BigInteger;
import java.util.Scanner;

public class CalculateN {

/**
* @param args
*/
public static void main(String[] args) {
System.out.print("请输入N：");
Scanner scanner=new Scanner(System.in);
int number=scanner.nextInt();
System.out.println(number+"!="+calculateN2(number));

}

public static long calculateN(int n) {
if(n==1 || n==0){
return 1;
}

return n*calculateN(n-1);
}

public static BigInteger calculateN2(int n) {
if(n==1 || n==0){
return BigInteger.valueOf(1);
}
return BigInteger.valueOf(n).multiply(calculateN2((n-1)));
}
}