JAVA语言 关于数组的基本处理

JAVA 语言关于数组的练习题

public class ArrayUtils{

    //1.计算数组中最大值
    public static int arrayMaxElement(int[] data){
		int max = data[0];
         for(int i = 1;i < data.length;i++){
			 if(data[i]>max){
				 max = data[i];
			 }
		 }
        return max;
    }
    
    //2.计算数组中最小值
    public static int arrayMinElement(int[] data){
        int min = data[0];
		for(int i = 0;i < data.length;i++){
			if(data[i] < min){
				min = data[i];
			}
		}
        return min;
    }
    
    
    //3.计算数组值之和
    public static int arrayElementSum(int[] data){
        int sum = 0;
		for(int i = 0;i<data.length;i++){
			sum+=data[i];
		}
        return sum;
    }
    
    //4.数组拼接
    public static int[] arrayJoin(int[] a, int[] b){
        int[] c = new int[a.length+b.length];
		for(int i = 0;i<a.length;i++){
			c[i] = a[i];
		}
		for(int j = 0;j<b.length;j++){
			c[a.length+j] = b[j];
		}
		printArray(c);
        return c;
    }

    //5.数组截取
    //[start, end)
    public static int[] arraySub(int[] data, int start , int end){
        if ((start<0)||(end<0)||((end-start)>data.length)|| (start > end)){
		  System.out.println("出错");
		  return null;
	  }
		int[] b = new int[end-start];
		for(int i = start;i<end;i++){
			b[i-start] = data[i];
		}
		printArray(b);
        return b ;
    }
    
    //6.数组打印
    public static void printArray(int[] data){
        for(int i = 0;i<data.length;i++){
			System.out.print(data[i]+" ");
		}
		System.out.print("\n");
    }
    
    //7.数组反转
    // 比如：[1,2,3,4] => [4,3,2,1]
    public static void printReversal(int[] data){
        int left = 0;
	  int right = data.length-1;
	  while(left<right){
		  int temp = data[left];
		  data[left] = data[right];
		  data[right] = temp;
		  left++;
		  right--;
	  }
		printArray(data);
    }
    
    public static void main(String[] args){
        int[] a =new int[]{1,2,3,4,5};
		int[] b = new int[]{2,4,6,8,0};
        System.out.println("数组中的最大值:"+arrayMaxElement(a));		
		System.out.println("数组中的最小值:"+arrayMinElement(a));
		System.out.println("数组之和:"+arrayElementSum(a));
		System.out.println("数组拼接:"+arrayJoin(a,b));
		System.out.println("数组截取:"+arraySub(a,2,4));
		printReversal(a);
             
    }
}

相应的结果如下图: