"Big Data-Phase II" Java Foundation Third day job

1. Defines a function that is dynamically extracting the maximum value of an element in int[].

    public static void main (String[] args) {                 system.out.println (GetMax (new int [0]));         int[] arr = new int[]{3,2,11,5};         system.out.println ("arr Maximum:"  + getmax (arr));     }    public static int getmax (Int[] arr) {         int temp = Integer.MIN_VALUE;         if  (arr == null | |  arr.length == 0)         {             system.out.print ("[Value error]");             return -1;        }        for  (int i = 0;i  < arr.length ;i++ )         {             if  (Temp < arr[i])              {                 temp = arr[i];             }        }         return temp;    }

2. Defines a function that queries the location of the first occurrence of the specified element from the array.

    public static void main (String[] args) {                 int[] arr = new  int[]{1,2,3,4,5,6,0,10};                 int index = searcharray (0, arr);             }    public static int searcharray (int  Num,int[] arr) {        if  (arr == null)          {             system.out.println ("Arr value cannot be null");                 return -1;        }         int index = -1;        for  (int i =  0;i < arr.length ;i++ )         {             if  (arr[i] == num)              {                 index = i;                 system.out.println ("Number:"  + num  +  ", existence Position:"  + index);                 return i;             }        }         System.out.println ("Can ' t search&nbsp Number: " + num);        return -1 ;     }

3. Define the function, complete the bubbling sort, and sink the large number.

    public static void main (String[] args) {                 int[] arr = sort (New &NBSP;INT[]{-1,-22,0,-3,1,-33});         out (arr);     }    public static int[] sort (Int[] arr) {         int temp = 0;        for   (int i = 0;i < arr.length ;i++ )          {            for  (int  j = i + 1; j < arr.length ;j++ )              {                 if  (Arr[i] > arr[j])                  {                     temp = arr[j];                     arr[j] = arr[i];                      arr[i] = temp;                 }            }         }        return arr;     }    public static void out (Int[] arr) {         for  (int i = 0;i < arr.length ;i++ )          {             System.out.print (arr[i] +  "\ T");        }         system.out.println ();     }

4. Binary find.

Class    test {public static void main (String[] args)  {     int[] arr = new int[] { 1, 2, 3, 4,  5, 6, 7, 8 };    int a = 0,b = arr.length  - 1,m = 0;    int x = 2;    while   (a <= b) {        m =  (a + b)  / 2;        if  (arr[m] == x) {             system.out.println ("Index is:"  + m) ;            break;         }else if  (X < arr[m])          {&NBSP;&NBSP;&NBSP;&NBSP;&Nbsp;       b = m - 1;         }else {            b =  m + 1;        }    }     }}

5. Defines a function that implements the transpose of the matrix. arr[i][j] = = arr[j][i];//the precondition is affirmative.

    public static void main (String[] args)  {         int arr[][] = {{1,2,3},{4,5,6},{7,8,9}};         //out (arr);         system.out.println ("------- -----------------");            arr =  Trans (arr);             out (arr);         }        public static int[][]  trans (Int[][] arr) {        for  (int i =  0;i < arr.length - 1 ;i ++ )          {            for  (int j  = i + 1; j < arr.length ;j ++ )              {                 int temp = arr[i][j];                 arr[i][j] = arr[j][i];                 arr[j][i] = temp;             }                     }         Return arr;    }    public static void out (int[][]  arr) {    for  (int i = 0;i < arr.length;i++)      {        for  (int j = 0;j < arr.length ;j  ++ )         {             system.out.print (arr[i][j] +  "\ T");         }            system.out.println ( );     }    }

6. Traverse three-dimensional groups and output each layer of the three-dimensional array horizontally.

The answer to the teacher's question is still not clear ...

    public static void main (String[] args)  {int[][][] arr  = { { { 1, 2, 3 }, { 4, 5, 6 }, {  7, 8, 9 } },{ { 10, 11, 12 }, { 13, 14, 15  }, { 16, 17, 18 } },{ { 19, 20, 21 }, {  22, 23, 24 }, { 25, 26, 27 } } };outhor (arr);     }    public static void outhor (Int[][][] arr) {         for  (int i = 0; i < arr.length  ;i++ )         {             for  (int j = 0 ; j < arr.length;  j++ ) &NBSP;&NBSP;&NBsp;         {                 for  (Int k = 0;k < arr[j][i]. length ;k++ )                  {                     system.out.print (arr[j][i][k] +  "\ T");                 }                 system.out.print ("|  "  );             }             system.out.println ();        }     }

7. Defines a class: Dog has the name Color Age cry ();

    public static void main (String[] args)  {         dog d = new dog ("Yellow",;     )    system.out.println ("Color:"  + d.getcolor ()  +  "   age:"  + d.getage ());                     }}class Dog{    private String color;     private int age;        public  Dog (string color,int age) {        this.color =  color;        this.age = age;    }     public void setcolor (String color) {         this.color = color;    }    public string getcolor () {         return color;    }    public  void setage (int age) {        this.age = age;     }    public int getage () {         return age;    }    public void cry () {        system.out.println ("barking ~ ~ ~");     }

9. Describe the heap area, stack area, when overflow, how to solve.

For:

Heap Area: Stores objects and member variables.

Stack area: Stores local variables and method memory.

Overflow: An object that consumes large memory resources, or overflows when it is recursive.

Workaround:

JAVA-XMS;

10.oop

Face objects: As with the process, it is a programming method.

Class: The abstraction of an object.

Object: The instantiation of the class.

Instance: = Object

Member variable: An object's property variable.

member function: The method of the object.

Public: A common modifier that provides various types of calls.

Private: A proprietary modifier that improves security and is only allowed in this class. Its properties can be changed by the Set,get method. For encapsulation.

Constructor: Constructs an initialization object. no return value.

This: is a member variable of an object, used for method references and property references in a class.

Static: Statically, decorated member variable, member function. , a class can also reference static members, and static methods can only access static members.

"Big Data-Phase II" Java Foundation Third day job