Pointer In C (In Depth) (Final) Part 4

Generic Pointer in C Programming

Generic pointer:

void pointer in c is known as generic pointer. Literal meaning of generic pointer is a pointer which can point type of data.

Example:

void *ptr;

Here ptr is generic pointer.

Pointer in C (In Depth) Part 3

Pointer to function in c programming

What will be output if you will execute following code?

int * function();

void main(){

auto int *x;

int *(*ptr)();

ptr=&function;

x=(*ptr)();

printf("%d",*x);

}

int *function(){

static int a=10;

return &a;

}

Output: 10

Explanation: Here function is function whose parameter is void data type and return type is pointer to int data type.

x=(*ptr)()

=> x=(*&functyion)() //ptr=&function

=> x=function() //From rule *&p=p

=> x=&a

So, *x = *&a = a =10

Pointer in C (In Depth) Part 2

Arithmetic Operation with Pointer in C Programming

Rule 1:

Address + Number= Address

Address - Number= Address

Address++ = Address

Address-- = Address

++Address = Address

--Address = Address

Pointer In C (In Depth) Part 1

POINTER

Pointer is a variable just like other variables of c but only difference is unlike the other variable it stores the memory address of any other variables of c. This variable may be type of int, char, array, structure, function or any other pointers. 

For examples:

(1) Pointer p which is storing memory address of a int type variable:

int i=50;

int *p=&i;

(2) Pointer p which is storing memory address of an array:

int arr[20];

int (*p)[20]=&arr;

String In JAVA

Strings

Definition:

Strings, which are widely used in Java programming, are a sequence of characters. In the Java programming language, strings are objects.

The Java platform provides the String class to create and manipulate strings.

Creating Strings

The most direct way to create a string is to write:


String greeting = "Hello world!";

Garbage Collector in Java

The Garbage Collector in JAVA

Some object-oriented languages require that you keep track of all the objects you create and that you explicitly destroy them when they are no longer needed. Managing memory explicitly is tedious and error-prone. The Java platform allows you to create as many objects as you want (limited, of course, by what your system can handle), and you don't have to worry about destroying them. The Java runtime environment deletes objects when it determines that they are no longer being used. This process is called garbage collection.
 

Data Structures Interview Questions and Answers

Q 1. What is data structure?

Ans.  A data structure is a way of organizing data that considers not only the items stored, but also their relationship to each other. Advance knowledge about the relationship between data items allows designing of efficient algorithms for the manipulation of data.

Q 2. List out the areas in which data structures are applied extensively?

Compiler Design, Operating System, Database Management System, Statistical analysis package, Numerical Analysis, Graphics, Artificial Intelligence, Simulation

SQL Query Part 2

Query 1.      Case stmt example

---

 Tables                           Query                                               Result

EMP_JB		SELECT id	ANSWER
		,job	===============
ID JOB		,CASE	ID  JOB		STATUS
		WHEN  job  =  'Sales'
10 Sales		THEN  'Fire'	10	Sales	Fire
20 Clerk		ELSE  'Demote'	20	Clerk	Demote
		END  AS  STATUS
		FROM emp_jb;

Query 2. Fetch  first  "n"  rowsexample

---

 Tables                           Query                                               Result

EMP_NM			SELECT	*	ANSWER
			FROM	emp_nm	=========
ID NAME			ORDER  BY  id  DESC		ID  NAME
			FETCH  FIRST  2  ROWS  ONLY;
10 Sanders					50	Hanes
20 Pernal					20	Pernal
50 Hanes

SQL Query Part 1

Query 1.      Join example

---

 Tables                           Query                           Result

---

Table 1                 Table 2 

EMP_NM			EMP_JB			SELECT	nm.id	ANSWER
							,nm.name	================
ID NAME			ID JOB				,jb.job	ID  NAME		JOB
						FROM	emp_nm  nm
10 Sanders			10 Sales				,emp_jb  jb	10	Sanders	Sales
20 Pernal			20 Clerk			WHERE	nm.id  =  jb.id	20	Pernal	Clerk
50 Hanes						ORDER  BY  1;

---

Query 2.    Leftouterjoin  example

---

 Tables                           Query                           Result

---

Table 1                 Table 2 

EMP_NM			EMP_JB			SELECT	nm.id	ANSWER
							,nm.name	================
ID NAME			ID JOB				,jb.job	ID  NAME		JOB
						FROM	emp_nm  nm
10 Sanders			10 Sales			LEFT  OUTER  JOIN		10	Sanders	Sales
20 Pernal			20 Clerk				emp_jb  jb	20	Pernal	Clerk
50 Hanes						ON	nm.id  =  jb.id	50	Hanes
						ORDER  BY  nm.id;

C Programming Question Part 3

Pattern Print with Unique and Extreme Logic

Pattern  1.	*** ** * ** ***
Code:	#include <stdio.h> main() { int i,x,j; for (i=2; i>=-2;i--) { x = 1 + 2*abs(i); for (j=1;j<=x;j++) printf("*"); printf("\n"); } }
Pattern 2.	RAJVEER A        E      J        E V        V E        J E        A REEVJAR
Code:	#include<conio.h> #include<string.h> void main() {      char str[20];       int i,j,k,len;       printf("Enter the String: ");       gets(str);       len=strlen(str);       puts(str);       printf("");       for(i=1;i<len-1;i++)       {             printf("%c",str[i]);             for(j=0;j<len-2;j++)                   printf(" ");             printf("%c\n",str[len-i-1]);       }       strrev(str);       puts(str); }
Pattern 3.	*  **    ***  ** *
Code:	#include <stdio.h> main() { int i,x,j; for (i=2; i>=-2;i--) { x = 1 + abs(i); for (j=1;j<=x;j++) printf(" "); for (j=1;j<=x;j++) printf("*"); printf("\n"); } }
Pattern 4.	1 01 101 0101
Code:	#include<stdio.h> #include<conio.h> void main() {   int i,j;   int count = 1;   clrscr();   for(i=1;i<=4;i++)   {         for(j=1;j<=i;j++)         {             printf("%d",(i+j+1)%2);                        }     printf("\n");      }   getch(); }