java入门-数组进阶

1.数组的复制

package step1;

import java.util.Scanner;

public class HelloWorld {
	public static void main(String[] args) {
		//动态构建arr1
		int[] arr1 = new int[3];
		Scanner sc = new Scanner(System.in);
		for(int i = 0 ; i< arr1.length ; i++){
			arr1[i] = sc.nextInt();
		}
		/********** Begin **********/
		//创建数组arr2
		int[] arr2 = new int[3];
       
		
		//使用for循环将arr1的数据复制给arr2
		 for(int i=0;i<3;i++){
            arr2[i]=arr1[i];
        }
			
		//输出arr2
		for(int i=0;i<3;i++)
		System.out.println(arr2[i]);
		
		/********** End **********/
	}
}

2.数组中元素的查找

package step2;

import java.util.Scanner;

public class HelloWorld {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		//str为要查找的字符串
		String str = sc.next();
		
		/********** Begin **********/
		//创建数组   arr  给数组赋值 {"张三","张三丰","张无忌","王二麻子","张富贵"}
		
		String[] arr = new String[]{"张三","张三丰","张无忌","王二麻子","张富贵"};  
		for(int i=0;i

3.交换算法

package step3;

import java.util.Scanner;

public class HelloWorld {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		/********** Begin **********/
		//将a的值赋给b   b的值赋给a
		int tmp = a;
        a = b;
        b = tmp;
		
		
		
		

		/********** End **********/
		System.out.println(a);
		System.out.println(b);
	}
	
}

4.排序

package step4;

import java.util.Arrays;
import java.util.Scanner;

public class HelloWorld {
	
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		//动态创建数组
		int[] arr = new int[sc.nextInt()];
		for(int i = 0 ; i< arr.length ; i++){
			arr[i] = sc.nextInt();
		}
		/********** Begin **********/
		for(int i=0;i

5.冒泡

package step5;

import java.util.Arrays;
import java.util.Scanner;

public class HelloWorld {
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		//动态创建数组
		int[] arr = new int[sc.nextInt()];
		for(int i = 0 ; i< arr.length ; i++){
			arr[i] = sc.nextInt();
		}
		/********** Begin **********/
	int l = arr.length;
    for(int i=0;iarr[j+1]){
                int tmp = arr[j];
                arr[j] = arr[j+1];
                arr[j+1] = tmp;
            }
        }
    }
	System.out.println(Arrays.toString(arr));	
		/********** End **********/
	}
}