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Java第八次

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1、编写一个简单程序,要求数组长度为5,分别赋值10,20,30,40,50,在控制台输出该数组的值.

package work;

public class work {
public static void main(String[] args) {
	int a[]={10,20,30,40,50};
	for (int i = 0; i < a.length; i++) {
		System.out.println(a[i]);
	}
}
}

 

 

 

2、将一个字符数组的值(neusofteducation)拷贝到另一个字符数组中。

package work;

public class work {
public static void main(String[] args) {
	char a[]={'n','e','u','s','o','f','t','e','d','u','c','a','t','i','o','n'};
	char[]b=new char[16];
    System.arraycopy(a, 0, b, 0, 16);
    for (int i = 0; i < a.length; i++) {
		System.out.print(a[i]);
	}
}
}

  

 

 

 3、给定一个有9个整数(1,6,2,3,9,4,5,7,8)的数组,先排序,然后输出排序后的数组的值。

Arrays.sort排序:

package work;

import java.util.Arrays;

public class work {
public static void main(String[] args) {
	int a[]={1,6,2,3,9,4,5,7,8};
	Arrays.sort(a);
	System.out.println("排序后");
	for (int i = 0; i < a.length; i++) {
		System.out.print(" "+a[i]);
	}
}
}

  

 

 

 冒泡排序:

package work;

import java.util.Arrays;

public class work {
public static void main(String[] args) {
	int a[]={1,6,2,3,9,4,5,7,8};
	for (int i = 0; i < a.length-1; i++) {
		for (int j = 0; j < a.length-1-i; j++) {
			if (a[j]>a[j+1]) {
				int temp=a[j];
                a[j]=a[j+1];
                a[j+1]=temp;
			}
		}
	}
	System.out.println("排序后");
	for (int i = 0; i < a.length; i++) {
		System.out.print(" "+a[i]);
	}
}
}

 

 

 

4、 输出一个double型二维数组(长度分别为5、4,值自己设定)的值。(知识点:数组定义和创建、多维数组初始化、数组遍历)

package work;

public class work {
public static void main(String[] args) {
	double [][]a=new double[5][4];
	for (int i = 0; i < a.length; i++) {
		for (int j = 0; j < a[i].length; j++) {
			a[i][j]=j;
			System.out.print(a[i][j]+" ");
		}System.out.println();
	}
}
}

  

 

 

 5、 在一个有8个整数(18,25,7,36,13,2,89,63)的数组中找出其中最大的数及其下标。(知识点:数组遍历、数组元素访问) [必做题]•

package work;

public class work {
public static void main(String[] args) {
	int a[]={18,25,7,36,13,2,89,63};
	int max=a[0];
	int index=0;
	for (int i = 0; i < a.length; i++) {
		if (a[i]>max) {
			max=a[i];
		index=i;
		}
	}
	
	System.out.println("数组中的最大值为"+max);
	System.out.println("下标为"+index);
}
}

  

 

 

 作业

6、将一个数组中的元素逆序存放(知识点:数组遍历、数组元素访问) [选作题]•

package work;

public class work {
public static void main(String[] args) {
	int a[]={18,25,7,36,13,2,89,63};
	System.out.println("倒序后为:");
	for (int i = 7; i >= 0; i--) {
		System.out.print (" "+a[i]);
	}
}
}

  

 

 

 7. 将一个数组中的重复元素保留一个其他的清零。(知识点:数组遍历、数组元素访问)

package work;

public class work {
public static void main(String[] args) {
	int a[]={18,25,7,36,13,2,89,63,25,18};
	for (int i = 0; i < a.length; i++) {
		for (int j = 0; j < a.length; j++) {
			if (a[i]==a[j] && i!=j) {
				a[j]=0;
			}
		}
	}
	for (int i : a) {
		System.out.print(" "+i);
	}
}
}

  

 

 

 8、给定一维数组{ -10,2,3,246,-100,0,5},计算出数组中的平均值、最大值、最小值。(知识点:数组遍历、数组元素访问)

package work;

public class work {
public static void main(String[] args) {
	int a[]={-10,2,3,246,-100,0,5};
	int max=a[0];
	int min=a[0];
	double sum=0;
	for (int i = 0; i < a.length; i++) {
		if (max<a[i]) {
			max=a[i];
		}
		if (min>a[i]) {
			min=a[i];
		}
		sum+=a[i];
	}
	sum=sum/7;
	System.out.println("最大值"+max);
	System.out.println("最小值"+min);
	System.out.println("平均值"+sum);
}
}

  

 

 

 9、使用数组存放裴波那契数列的前20项 ,并输出 1 1 2 3 5 8 13 21

package work;

public class work {
public static void main(String[] args) {
        int[] a = new int[20];
        a[0] = 1;
        a[1] = 1;
        for (int i = 2; i < a.length; i++) {
            a[i] = a[i - 1] + a[i - 2];
        }
        for (int i = 0; i < 8; i++) {
            System.out.print(a[i] + " ");
        }
    }

}

  

 

 

 10、生成一个长度为10的随机整数数组(每个数都是0-100之间),输出,排序后,再输出

package work;
import java.util.Arrays;
import java.util.Random;
public class work {
public static void main(String[] args) {
	 Random r = new Random();
	 int a[] = new int[10];
	 for (int i = 0; i < a.length; i++) {
		 a[i] = r.nextInt(101);
	 }
	 for (int i = 0; i < a.length; i++) {
		 System.out.print(a[i] + " ");
	}
	 Arrays.sort(a);
	 System.out.println();
	 for (int i = 0; i < a.length; i++) {
		System.out.print(a[i]+" ");
	}
}

}

  

 

 

 

标签:Java,int,work,System,第八次,数组,public,out
来源: https://www.cnblogs.com/cuibaoyuan/p/14710315.html