day6-Java课堂练习
package day6;
import java.util.Scanner;
public class 函数练习 {
static double average(double a,double b){//average
return (a+b)/2;
}
static int func(int n){//n!
if (n==1)
return 1;
else
return n*func(n-1);
}
static int fun(int n,int total){
for (int i=1; i<=n; i++)
total = total * i;
return total;
}
static void row(int n){
for (int i=0; i<n; i++)
System.out.print("* ");
}
static void column(int n){
for (int i=0; i<n; i++){
row(n);
System.out.println();
}
}
static void count(int[] num){
for (int i=0;i<num.length; i++)
num[i] *= 2;
}
static int[] countbat(int[] num){
for (int i=0;i<num.length; i++)
num[i] *= 2;
return num;
}
static int count1(int[] num){
int sum = 0;
for (int i=0;i<num.length; i++)
sum += num[i];
num[0] = sum;
return num[0];
}
static void multiply(){
for (int i=1; i<=9; i++){
乘法表(i);
System.out.println();
}
}
static void 乘法表(int i){
for (int j=1; j<=i; j++){
System.out.print(i+"*"+j+"="+i*j+"\t");
}
}
static int length(int[] A){
return A.length;
}
static int[] 合并数组(int[] C){
int[] A = new int[]{1,2,3,4,5};
int[] B = {6,7,8,9,10};
int index = 0;
for (int j=0; j<A.length; j++)
C[index++] = A[j];
for (int i=0; i<B.length; i++)
C[index++] = B[i];
return C;
}
public static void main(String[] args) {
System.out.println(func(5)+" "+fun(5,1));
System.out.println(average(2,3));
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
column(n);
int[] arr = {1,2,3,4,5};
System.out.println("arr[0]="+count1(arr));
count(arr);
System.out.println("arr数组元素都乘以二输出:");
for (int i=0; i<arr.length; i++)
System.out.print(arr[i]+" ");
System.out.println();
multiply();
int[] C = new int[10];
int[] array = 合并数组(C);
for (int i=0; i<array.length; i++)
System.out.print(array[i]+" ");
}
}