JAVA基础知识测试题：

1.    

public class Dome1 {

	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		  String mun = input.nextLine();  
	        int cd = mun.length();  
	        int num = 0; 
	        int abc = 0; 
	        int space = 0; 
	        int other = 0;
	        for (int i = 0; i < cd; i++) {  
	            char s = mun.charAt(i);  
	            if(s >= '0' &&  s <= '9') { 
	                num++;  
	            }else if((s>='a'&& s<='z') || (s>='A'&& s<='Z')) {  
	                abc++;  
	            }else if(s == ' ') {  
	                space++;  
	            }else {    
	                other++;  
	            }  
	        }  
	        System.out.println("数字个数："+num);  
	        System.out.println("英文字母个数："+abc);  
	        System.out.println("空格个数："+space);  
	        System.out.println("其他字符个数："+other);  
	}
}

2.

public class Dome2 {

	public static void main(String[] args) {
		int num [] = new int [10];        //数组长度
		Scanner input = new Scanner(System.in); 
		System.out.println("请输入10个整数：");
		for (int i = 0; i < num.length; i++) {
			int  sum = input.nextInt();
			  num [i] = sum;
		} 
	       for (int i = 0; i < num.length-1; i++) {  
               for (int j = 0; j < num.length-1-i; j++) {  
                if(num[j]>num[j+1]) {  
                    int a = num[j];  
                   num[j]=num[j+1];  
                    num[j+1]=a;  
                }  
            }  
        }  
		System.out.println("十个整数排列结果：");
		for (int i = 0; i < num.length; i++) {
			System.out.print(num[i]+" ");
		}
	}
}

3.

public class Dome3 {

	public static void main(String[] args) {
		int [] arr = new int []{10,20,30};
		int [] arr2 = new int []{40,50,60};
		int [] arr3 = new int[6];
		System.out.print("第一个数组中的元素:");
                for (int i = 0; i < arr.length; i++) {
		System.out.print(arr[i]+" ");	
	       }
                System.out.print("\n第二个数组中的元素：");
                for (int i = 0; i < arr2.length; i++) {
		System.out.print(arr2[i]+" ");
	       }
                System.out.print("\n俩个数组合并后：");
                for (int i = 0; i <arr3.length ; i++) {
    	        arr3[i] = arr[i];
    	        arr3[i] = arr2[i]-1;
    	        if(i<arr.length) {
                arr3[i] = arr[i];
    	        }else {
                arr3[i] = arr2[i-(arr.length)];
    	       }
	   }
               for (int i = 0; i < arr3.length; i++) {
		System.out.print(arr3[i]+" ");
	      }
               System.out.print("\n逆序后排列：");
               for (int i = arr3.length-1;i>=0; i--) {
   		System.out.print(arr3[i]+" ");
   	      }
	}
}

4.

public class Dome4 {
	
	public static void main(String[] args) {
		double getAvg = 0;//平均身高
	        double sum = 0;  //总数
		Scanner input = new Scanner(System.in);
                String name [] = new String [5];
                Double height [] =  new Double [5];
               for (int i = 0; i < name.length; i++) {
		System.out.print("请输入第"+(i+1)+"位同学的姓名，身高：");
		  name [i] = input.next();
		  height [i] = input.nextDouble();
		  sum+=height[i];
	       }
                 getAvg = sum/5.0;
                 System.out.println("平均身高是："+getAvg+"米");
	}

}