What syntax is used for grep() function?

1189

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938

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311

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898

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228

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749

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1120

Hello friends !!! I’am Abhinav Ranjan Sinha College- L.K.C.T(Indore) I just want to express my personnal experience of getting placed at Consagous Technologies,to all freshers who are in search of the job. On 25th of Feb 2011 there was a campus drive of Consagous Technologies in our college.That was the second time any software company is coming to our college for batch, I was very excited. Firstly, they started with a seminar, a small introduction about the company.Then as the first round of the placement process, they conducted GD, in every group there was 20 students, and in the GD they just given the topics on the current affairs ,like- Global warming, Science is a curse or boon, girls are superior than boys?, etc. Then after half an hour the result of GD was announced , and fortunetly I was selected among the 150 other students. Then there was a written round, that was fully Technical , the question paper consists of total 50 questions out which 45 are optional and the rest of the 5 questions are not optional. Some of them which I remember are- 1.when we pass an argument to a function , then how it is being interpreted? Ans- Address of the first element of an array. 2.how the size of structure can be determined? 3.Complexity of binary search algorithm? Ans-0(logn) 4.what does the symbol << do in c++? 5.what does (.) dot operator do? 6.what is RTTI? 7.What is containership? And many more questions related to data structure on complexity, C program output, etc Then the result was declared on the next day, total 45 students are short leasted out of 150(approx) and the further rounds of Technical and HR are after two days. Then on 28th of Feb 2011 we are called for the next rounds, and that was the toughest time ever as my turn came almost at last , firstly my name was announced for the Technical round, there when I entered there are 3 persons inside the room who are taking the interview, as I entered they asked me to reduce the speed of the fan, I went to the switch board but the regulator was not working , then they told me to switch it off. Then , they offerd me to have a seat, there they asked me about- 1. what is your area of interest? 2. what is recursion? 3. write a program of factorial using recursion. 4. differentiate between My sql and Sql server. 5. they asked me questions related to my minor project. 6. what does get and post method do? 7. what is structure? 8. what is union? Out of which I have given answers of the many of them. Then I was called for the PI (personnmal interview) , I was very tired as it was 6:30 and I was waiting for my turn from 11’o clock onwards. But as I was very much exited , I just prayed to God and entered in the room, As I entered I saw two persons there inside the room I wished both of them, and they offerd me the chair, I replied with thank you sir thank you mam. Then the first question which I was asked there is- 1.Tell me something about yourself? Then, 2.they asked me of my strengths. 3.then suddenly they started asking aptitude questions, and the main thing is that they are not repeating the questions, you have to listen it very carefully. And the questions are like— Que- a man moves 50 km away from his house in the north direction, then he turns left and moves 50 km , and then again he turns left and moves 50 km, then at which place he is from his house and at what distance? Que- the ratio of the age of the two friends are in the ratio 6:5 then there ratio becomes 8:7 , so how many years they will it takes to gain this ratio? 4.where do you see yourself after 5 years? 5.tell me your 5 such skills which you can give to our organization. 6.what do you know about our company? They both are very calm and are of very good nature, and they are very supportive which helped me a lott . And just after half an hour the results had been declared and fortunetly with God’s Grace I got selected, that was the one of the very most imported and cherishable moment of my life. All The Best to all my dear friends , and I wish you for your bright future. And , at last but not the least, I would like to thanks to Consagous Technologies to give me such a big opportunity to prove myself in my life, thank you so much.

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Question 1 [8] Draw a UML class diagram for the code fragment given below: public class StringApplet extends Applet { private Label sampleString; private Button showTheString; private ButtonHandler bHandler; private FlowLayout layout; public StringApplet() { sampleString = new Label(" "); showTheString = new Button (" Show the String"); bHandler = new ButtonHandler(); layout = new FlowLayout(); showTheString.addActionListener(bHandler); setLayout(layout); add(sampleString); add(showTheString); } class ButtonHandler implements ActionListener { public void actionPerformed(ActionEvent e) { samplestring.setText("Good Morning"); } } } Note: The methods need not be indicated on the diagram. 6 Question 2 [10] The following program reads data (details of students) from a file named students.txt and converts it into e-mail addresses. The results are written to a file named studentemail.txt. students.txt consists of a number of lines, each containing the data of a student in colon delimited format: Last Name:First Name:Student Number Each input record is converted to an e-mail address and written to studentemail.txt in the following format: the first character of the last name + the first character of the first name + the last four digits of the student number + “@myunisa.ac.za” import java.io.*; public class EmailConverter { public static void main(String[] args) throws IOException { BufferedReader input = new BufferedReader(new FileReader ("students.txt")); PrintWriter output = new PrintWriter(new FileWriter ("studentemail.txt")); String line = input.readLine(); while (line != null) { // Extract the information for each student String[] items = line.split(":"); // Generate the email address String email = "" + items[0].charAt(0) + items[1].charAt(0) + items[2].substring(4,8) + "@myunisa.ac.za"; email = email.toLowerCase(); // Output output.println(email); line = input.readLine(); } input.close(); output.close(); } } Rewrite the class so that it handles possible errors that may occur. In particular, it should do the following: • It should catch at least three appropriate exceptions that might occur, and display suitable messages. • At this stage, the program will not run correctly if there is an empty line in the input file. Change the program so that if an empty line is encountered, an exception is thrown and the empty line is ignored. This exception should be handled with the display of a suitable error message. • Before the e-mail address is added to the output file, check if the student number has 8 digits. If not, throw an InvalidFormatException (which the program should not handle itself). COS2144/102 7 Question 3 [12] 3.1 Say you want to store the information about a number of pets in an array. Typical information that you could store for each pet (where relevant) would be • Breed of animal • Animal's name • Its birth date • Its sex • Whether it has been sterilised or not • When it is due for its next inoculation • When it last had its wings clipped For each type of pet (eg. dog, cat or bird) you would typically define a class to hold the relevant data. Note: You do not need to implement these classes. Just answer the following questions. 3.1.1 What would be the advantage of creating a superclass (eg. Pet) and declaring an array of Pet objects over simply using an array of Objects, storing each of the instances of the different pet classes (eg. Dog, Cat or Bird) in it? 3.1.2 Would you define Pet as a class or as an interface? Why? (2) (2) 3.2 Consider the following class: public class Point { protected int x, y; public Point(int xx, int yy) { x = xx; y = yy; } public Point() { this(0, 0); } public int getx() { return x; } public int gety() { return y; } public String toString() { return "("+x+", "+y+")"; } } Say you wanted to define a rectangle class that stored its top left corner and its height and width as fields. 3.2.1 Why would it be wrong to make Rectangle inherit from Point (where in fact it would inherit the x and y coordinates for its top left corner and you could just add the height and width as additional fields)? (1) 8 Now consider the following skeleton of the Rectangle class: public class Rectangle { private Point topLeft; private int height, width; public Rectangle(Point tl, int h, int w) { topLeft = tl; height = h; width = w; } public Rectangle() { this(new Point(), 0, 0); } // methods come here } 3.2.2 Explain the no-argument constructor of the Rectangle class given above. 3.2.3 Write methods for the Rectangle class to do the following: • a toString() method that returns a string of the format "top left = (x, y); height = h; width = w " where x, y, h and w are the appropriate integer values. • an above() method that tests whether one rectangle is completely above another (i.e. all y values of the one rectangle are greater than all y values of the other). For example, with the following declarations Rectangle r1 = new Rectangle(); Rectangle r2 = new Rectangle(new Point(2,2), 1, 4); the expression r2.above(r1) should give true, and r2.above (r2) should give false. (You can assume that the height of a rectangle is never negative.) (2) (5) Question 4 [8] 4.1 Supply contracts (in the form of comments specifying pre- and post conditions) for the enqueue() method of the LinkedQueue class given in the Appendix. (2) 4.2 Let Thing be a class which is capable of cloning objects, and consider the code fragment: Thing thing1 = new Thing(); //(1) Thing thing2 = thing1; //(2) Thing thing3 = (Thing) thing1.clone(); //(3) Explain how the objects thing2 and thing3 differ from each other after execution of the statements. (4) COS2144/102 9 Question 5 [15] Consider the following classes, illustrating the Strategy design pattern: import java.awt.*; abstract class Text { protected TextApplet tA; protected Text(TextApplet tApplet) { tA = tApplet; } abstract public void draw(Graphics g); } class PlainText extends Text { protected PlainText(TextApplet tApplet) { super(tApplet); } public void draw(Graphics g) { g.setColor(tA.getColor()); g.setFont(new Font("Sans-serif", Font.PLAIN, 12)); g.drawString(tA.getText(), 20, 20); } } class CodeText extends Text { protected CodeText(TextApplet tApplet) { super(tApplet); } public void draw(Graphics g) { g.setColor(tA.getColor()); g.setFont(new Font("Monospaced", Font.PLAIN, 12)); g.drawString(tA.getText(), 20, 20); } } public class TextApplet extends java.applet.Applet { protected Text text; protected String textVal; protected Color color; public String getText() { return textVal; } public Color getColor() { return color; } public void init() { textVal = getParameter("text"); String textStyle = getParameter("style"); String textColor = getParameter("color"); if (textStyle == "code") text = new CodeText(this); else text = new PlainText(this); if (textColor == "red") color = Color.RED; else if (textColor == "blue") color = Color.BLUE; else color = Color.BLACK; } public void paint(Graphics g) { text.draw(g); 10 } } The Text class is more complicated than it should be (there is too much coupling between the Text and TextApplet classes). By getting rid of the reference to a TextApplet object in the Text class and setting the colour in the paint() method, one could turn the Text class into an interface and simplify the strategy classes considerably. 5.1 Rewrite the Text and PlainText classes to do what is described above. (6) 5.2 Explain the consequent changes that are necessary to the TextApplet class. (4) 5.3 Write an additional strategy class called FancyText (to go with your simplified strategy classes) to allow fancy text to be displayed for the value "fancy" provided for the style parameter. It should use the font Font ("Serif", Font.ITALIC, 12). (3) 5.4 Explain what changes are necessary to the TextApplet class for this. (2) Question 6 [9] 6.1 In what situations (in general) would you use a TreeMap? (3) 6.2 In what situations (in general) would you use a HashSet to store a collection of values? (3) 6.3 Name three software design patterns (besides the Strategy pattern) that are covered in the syllabus of COS2144. (3) Question 7 [8] Consider the following class and answer the questions below it: public class StackWithGuard extends Stack { public StackWithGuard(int size) { super(size); } synchronized public boolean isEmpty() { return super.isEmpty(); } synchronized public boolean isFull() { return super.isFull(); } synchronized public int getSize() { return super.getSize(); } synchronized public void push(Object obj) { try { while (isFull()) { wait(); } } catch (InterruptedException e) {} super.push(obj); COS2144/102 11 notify(); } synchronized public Object pop() { try { while (isEmpty()) { wait(); } } catch (InterruptedException e) {} Object result = super.pop(); notify(); return result; } public static void main(String args[]) { StackWithGuard stack = new StackWithGuard(5); new Producer(stack, 15).start(); new Consumer(stack, 15).start(); } } Note: The Stack class is provided in the Appendix. Note also: The following questions all refer to the pop() method of the StackWithGuard class given above. 7.1 What does the synchronized keyword ensure for this method? (2) 7.2 Why is a while loop used to test whether the stack is empty? In other words, why wouldn't the following if statement be sufficient? if (isEmpty()) { wait(); } (2) 7.3 Why is the result of popping (provided by the inherited pop() method) stored in a temporary variable? In other words, why wouldn't the following statement be sufficient? return super.pop(); (2) 7.4 Why is the while loop placed in a try-catch structure? (2) Appendix The LinkedQueue class: public class LinkedQueue implements Queue { private Node first, last; private int count; public LinkedQueue() { first = last = null; count =0; } public int size() { return count; } public boolean isEmpty() { return (count == 0); 12 } public void enqueue(Object o) { Node node = new Node(); node.element = o; node.next = null; node.prev = last; if (last != null){ last.next = node; } else { last = first = node; } last = node; count++; } public void dequeue() { if ((first!= null) & (first.next!=null)) { first = first.next; first.prev = null; count--; } else { first = last = null; count--; } } public Object front() { return first; } } class Node { Object element; Node next, prev; } The Stack class: public class Stack { protected Object rep[]; protected int top = -1; protected int size = 0; protected int count = 0; public Stack(int size) { if (size > 0) { this.size = size; rep = new Object[size]; } } public boolean isFull() { return (count == size); } public boolean isEmpty() { return (count == 0); } public int getSize() { return size; } public void push(Object e) { if (e != null && !isFull()) { COS2144/102 13 top++; rep[top] = e; count ++; } } public Object pop() { Object result = null; if (!isEmpty()) { result = rep[top]; top--; count--; } return result; } }

2771

What is java thread dump, how can we get java thread dump of a program?

1014

What is the difference between sdk1.7 and sdk1.8?

647

What is service request management?

974

What is Remarketing Audience and how to generate this list?

539

Does hibernate cache data?

387

We used asynchronous server communication for a long time, what new thing is ajax bringing?

947