Answer:
You have to like it to be successful in photography.
Explanation:
Answer:
Reference
Explanation:
The Reference type variable is such type of variable in C# that holds the reference of memory address instead of value. Examples for reference type are classes, interfaces, delegates and arrays.
We can pass parameters to the method by reference using <em>ref </em>keyword
It’s mandatory to initialize the variable value before we pass it as an argument to the method in c#
For example,
int x = 10; // Variable need to be initialized
Add(ref x); // method call
If you pass parameters by reference in method definition, any changes made to it affect the other variable in method call.
Here's a sample program:
using System;
namespace ConsoleApplication
{
public class Test
{
public static void Main()
{
int i = 10;
Console.WriteLine("i=" + i);
Add(ref i);
Console.WriteLine("i=" + i);
Console.ReadLine();
}
public static void Add( ref int j)
{
j = j + 10;
Console.WriteLine("j="+j);
}
}
}
Output:
i=10
j=20
i=20
Answer:
This is the complete correct program:
#include <stdio.h>
#include<sys/types.h>
#include<unistd.h>
int value = 128;
int main()
{
pid_t pid;
pid=fork();
if (pid==0) /* child process */
{
value +=8;
return 0; }
else if (pid > 0) {/* parent process */
wait (NULL);
printf ("PARENT: value =%d\n" ,value); /* LINEA */
return 0;
}
}
The output of the LINE A is:
PARENT: value = 128
Explanation:
The fork() function used in the program creates a new process and this process is the child process. The child process is same as the original process having its own address space or memory.
In the child process the value of pid is 0. So the if condition checks if pid==0. Then the child process adds 8 to the value of its variable according to the following statement
value +=8;
Now the original process has value = 128. In else if part the parents process has the value of pid greater than zero and this portion of the program is of the parent process :
else if (pid > 0)
{ wait (NULL);
printf ("PARENT: value =%d\n" ,value);
return 0; }
So the value 128 is printed at the end in the output.
wait(NULL) is used to wait for the child process to terminate so the parent process waits untill child process completes.
So the conclusion is that even if the value of the variable pid is changed in the child process but it will not affect the value in the variable of the parent process.
The format for the UPDATE command is the word UPDATE, followed by the name of the table to be updated. The next portion of the command consists of the word <u>SET</u>, followed by the name of the column to be updated, an equals sign, and the new value.
Explanation:
- An Update Query is an action query (SQL statement) that changes a set of records according to criteria you specify.
- The SQL UPDATE Query is used to modify the existing records in a table. You can use the WHERE clause with the UPDATE query to update the selected rows, otherwise all the rows would be affected.
- Update Queries let you modify the values of a field or fields in a table.
<u>UPDATE Syntax
</u>
- UPDATE table_name
- SET column1 = value1, column2 = value2, ...
- WHERE condition;
UPDATE table_name SET column1 = value1, column2 = value2, etc WHERE condition;
- table_name: name of the table
- column1: name of first , second, third column....
- value1: new value for first, second, third column....
- condition: condition to select the rows for which the
- values of columns needs to be updated.
Answer:
/*C++ program that prompts user to enter the name of input file(input.txt in this example) and print the sum of the values in the file to console. If file dosnot exist, then close the program */
//header files
#include <fstream>
#include<string>
#include <iostream>
#include <cstdlib> //needed for exit function
using namespace std;
//function prototype
int fileSum(string filename);
int main()
{
string filename;
cout << "Enter the name of the input file: ";
cin >> filename;
cout << "Sum: " << fileSum(filename) << endl;
system("pause");
return 0;
}
/*The function fileSum that takes the string filename and
count the sum of the values and returns the sum of the values*/
int fileSum(string filename)
{
//Create a ifstream object
ifstream fin;
//Open a file
fin.open(filename);
//Initialize sum to zero
int sum=0;
//Check if file exist
if(!fin)
{
cout<<"File does not exist ."<<endl;
system("pause");
exit(1);
}
else
{
int value;
//read file until end of file exist
while(fin>>value)
{
sum+=value;
}
}
return sum;
}//end of the fileSum
Explanation:
This is a C++ program that prompts user to enter the name of input file(input.txt in this example) and print the sum of the values in the file to console. If file dosnot exist, then close the program.
Check attachment for sample output screenshot.
