Java Programming

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What will be the output of the program? public class Sample { final static short a = 2; public static int b = 0; public static void main(String [] args) { for (int c=0; c < 4; c++) { switch (c) { case a: System.out.print("a "); default: System.out.print("default "); case a-1: System.out.print("a-1 "); break; case a-2: System.out.print("a-2 "); } } } }

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What is the output of this program? 1. class Crivitch { 2. public static void main(String [] args) { 3. int x = 10; 4. 5. do { } while (x++ < y); 6. System.out.println(x); 7. } 8. } Which statement, inserted at line 4, produces the output 12?

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What will be the output of the program? Given: 10. int x = 0; 11. int y = 10; 12. do { 13. y--; 14. ++x; 15. } while (x < 5); 16. System.out.print(x + "," + y); What is the result?

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What is the output of this program? class selection_statements { public static void main(String args[]) { int var1 = 5; int var2 = 6; if ((var2 = 1) == var1) System.out.print(var2); else System.out.print(++var2); } }

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Fill in the appropriate data type for the Java switch statement: switch (____) { case value1: ... case value2: ... default: System.out.println("Hello"); }

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French curly braces { } is a must if the for loop executes more than one statement. State true or false.

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What will be the output of the program? for(int i = 0; i < 3; i++) { switch(i) { case 0: break; case 1: System.out.print("one "); case 2: System.out.print("two "); case 3: System.out.print("three "); } } System.out.println("done");

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What will be the output of the program? int i = 1, j = -1; switch (i) { case 0, 1: j = 1; /* Line 4 */ case 2: j = 2; default: j = 0; } System.out.println("j = " + j);

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What will be the output of the program? public class Sample { public static void main(String [] args) { int i = 10; do while ( i < 10 ) System.out.print("The value of i is " + i); while ( i > 10 ) ; } }

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Predict the output. class X { void display(int a) { System.out.println("INT"); } void display(double d) { System.out.println("DOUBLE"); } } public class Sample { public static void main(String[] args) { new X().display(100); } }

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Observe the code public class Sample { public static void main(String [] args) { int x = 6; Sample p = new Sample(); p.display(x); System.out.print(" main x = " + x); } void display(int x) { System.out.print(" display x = " + x++); } } Given in command line - java Sample - What is the result?

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Given: public class Message { String msg; int noOfWords; public Message() { msg += " Thank you"; } public Message(int noOfWords) { this.noOfWords = noOfWords; msg = "Welcome"; Message(); } public static void main(String args[]) { Message m = new Message(5); System.out.println(m.msg); } } What will be the output ?

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Given classes defined in two different files: 1. package p1; 2. public class Test { 3. public static void display(String [] a) { /* some code */ } 4. } 1. package p2; 2. public class TestMain { 3. public static void main(String[] args) { 4. String [] names = new String[10]; 5. // insert code here 6. } 7. } Identify the statement to be written in line 5 in class TestMain to call the display method of class Test.

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What is the outcome of the code? public class Item { private String description; public String getDescription() { return description; } public void setDescription(String description) { this.description = description; } public static void modifyDesc(Item item,String desc) { item=new Item(); item.setDescription(desc); } public static void main(String[] args) { Item it=new Item(); it.setDescription("Gobstopper"); Item it2=new Item(); it2.setDescription("Fizzylifting"); it.modifyDesc(it,"Scrumdiddlyumptious"); System.out.println(it.getDescription()); System.out.println(it2.getDescription()); } }

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switch(a) { default: System.out.println("Welcome"); } Of which data types can the variable a be? 1. long 2. byte 3. int 4. char 5. float 6. short

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Predict the output. public class Test { public static void main(String args[]) { int a = 2, b = 0; for ( ; b < 20; ++b) { if (b % a == 0) continue; else if (b == 10) break; else System.out.print(b + " "); } } }

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What will be the output of the following code? int i=20; if(i>10) { System.out.println( "The value of i is "+i); i++; if(i%2!=0) break; }

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class Sample{ private double num = 100; private int square(int a){ return a*a; } } public class Test{ public static void main(String args[]){ Sample obj = new Sample(); System.out.println(obj.num); System.out.println(obj.square(10)); } }

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Choose the appropriate access specifier for the attribute value so that it can be accessed from anywhere. class Test { public int value; }

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Consider the below code snippet and determine the output. class Student { private int studentId; private float average; } class Test { public static void main(String a[]) { Student s=new Student(); s.studentId=123; System.out.println(s.studentId); } }

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The below code snippet shows an error cannot find symbol: System.out.println("BookId:"+bobj.getId()); public class Book { private int bookId; private double bookPrice; public int getBookId() { return bookId; } public void setBookId(int bookId) { this.bookId = bookId; } public double getBookPrice() { return bookPrice; } public void setBookPrice(double bookPrice) { this.bookPrice = bookPrice; } } public class Test { public static void main(String[] args) { Book bobj=new Book(); bobj.setBookId(123); bobj.setBookPrice(500); System.out.println("BookId:"+bobj.getId()); System.out.println("BookPrice:"+bobj.getBookPrice()); } } Analyze the above code and select the correct reason for the error.

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Observe the below code. public class Student { private int id; private String name; private char grade; //Constructor 1 public Student() { id=0; name= " "; } //Constructor 2 public Student(int id, String name) { this.id=id; this.name=name; } } Choose the constructor that is invoked, when an object is created as shown below. new Student(); Constructor 1 new Student(54, "John"); Constructor 2

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Observe the code below. public class Student { int studentId; String name; char grade; public Student(int studentId, String name, float mark) { this.studentId = studentId; this.name=name; calculateGrade(mark); } public void calculateGrade(float mark){ if(mark>90) grade='A'; else grade='B'; } } For the code Student s = new Student(1,"Peter",95); What will be the output?

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Observe the below class. class Product{ int productId; String productName; Product { productId=0; productName= ; } Product(int id, String name) { //access Product() ---- Line 1 productId=id; productName=name; } } Identify the valid option which is used to invoke the no argument constructor, Product(), at Line 1.

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Given the class Book and Library in two different packages : 1. package model; 2. public class Book { 3. private static void countBook { } 4. } 1. package util; 2. public class Library { 3. public static void main(String[] args) { 4. // insert code here 5. } 6. } What is required at line 4 in class Library to use the countBook method of Book class?

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Assume class Calculator in package p1 and CalculatorService class in package p2 as shown below. package p1; public class Calculator { __________ static void calculate(){ //some code here } } package p2; import p1.Calculator; public class CalculatorService { public void display(){ Calculator.calculate(); } } What can be the valid access specifier for the calculate method in Calculator class so that it can be accessed from CalculatorService class?

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Choose the correct order of the Java code fragments: 1) public class Main, 2) import java.util.Scanner;, 3) {, 4) // Some code here, 5) }, 6) package test;

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For the below code, what are the valid ways to invoke display method in the main method. public class Test { public static void display(){ } } public class Main { public static void main(String a[]){ //Invoke the display method } }

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class ArrayTest { public static void main(String args[]) { int[] primes = new int[10]; primes[0] = "a"; System.out.println(primes[0]); } } What will be the result of compiling and executing the above code?

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class TestArray { public static void main(String args[]) { int arr_sample[] = new int[2]; System.out.println(arr_sample[0]); } } What will be the result of compiling and executing the above code?

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What is the output of this program? class Output { public static void main(String args[]) { int a1[] = new int[10]; int a2[] = {1, 2, 3, 4, 5}; System.out.println(a1.length + " " + a2.length); } }

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package edu.ABC.model; public class Account { public static final float INTERTEST_RATE = 7.5; } Identify the correct options from the classes provided below.

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Predict the Output of following Java Program. class Test { int x = 10; public static void main(String[] args) { System.out.println(x); } }

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Given: public class ItemTest { private final int id; public ItemTest(int id) { this.id = id; } public void updateId(int newId) { id = newId; } public static void main(String[] args) { ItemTest fa = new ItemTest(42); fa.updateId(69); System.out.println(fa.id); } } What is the result?

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Predict the output of the below code : import java.util.regex.*; public class TestRegEx{ public static void main(String args[]) { Pattern p = Pattern.compile(".ech"); Matcher m = p.matcher("tech"); boolean b = m.matches(); System.out.println(b); } }

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What will be the output of the program? public class Sample { final static short a = 2; public static int b = 0; public static void main(String [] args) { for (int c=0; c < 4; c++) { switch (c) { case a: System.out.print("a "); default: System.out.print("default "); case a-1: System.out.print("a-1 "); break; case a-2: System.out.print("a-2 "); } } } } }

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What is the output of this program? 1. class Crivitch { 2. public static void main(String [] args) { 3. int x = 10; 4. 5. do { } while (x++ < y); 6. System.out.println(x); 7. } 8. } Which statement, inserted at line 4, produces the output 12?

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Fill in the appropriate data type for the Java switch statement: switch (____) { case value1: ... case value2: ... default: System.out.println("Hello"); }

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What is the output of this program? class selection_statements { public static void main(String args[]) { int var1 = 5; int var2 = 6; if ((var2 = 1) == var1) System.out.print(var2); else System.out.print(++var2); } }

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What will happen when the following code is compiled and run in Java 1.8? int i = 1, j = -1; switch(i) switch (i) { case 0, 1: j = 1; /* Line 4 */ case 2: j = 2; default: j = 0; } System.out.println("j = " + j);

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What will be the output of the program? for(int i = 0; i < 3; i++) { switch(i) { case 0: break; case 1: System.out.print("one "); case 2: System.out.print("two "); case 3: System.out.print("three "); } } System.out.println("done");

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What will be the output of the program? Given: 10. int x = 0; 11. int y = 10; 12. do { 13. y--; 14. ++x; 15. } while (x < 5); 16. System.out.print(x + "," + y); What is the result?

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French curly braces { } is a must if the for loop executes more than one statement. State true or false.

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What will be the output of the program? public class Sample { public static void main(String[] args) { int i = 10; do while (i < 10) { System.out.print("The value of i is " + i); } while(i>10); while (i > 10); } }

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Predict the output. class X { void display(int a) { System.out.println("INT"); } void display(double d) { System.out.println("DOUBLE"); } } public class Sample { public static void main(String[] args) { new X().display(100); } }

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Observe the code public class Sample { public static void main(String [] args) { int x = 6; Sample p = new Sample(); p.display(x); System.out.print(" main x = " + x); } voiddisplay(intx){ void display(int x) { System.out.print(" display x = " + x++); } } Given in command line - java Sample - What is the result?

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Given classes defined in two different files: 1. package p1; 2. public class Test { 3. public static void display(String [] a) { /* some code */ } 4. } 1. package p2; 2. public class TestMain { 3. public static void main(String[] args) { 4. String [] names = new String[10]; 5. // insert code here 6. } 7. } Identify the statement to be written in line 5 in class TestMain to call the display method of class Test.

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What is the outcome of the code? public class Item { private String description; public String getDescription() { return description; } public void setDescription(String description) { this.description = description; } public static void modifyDesc(Item item,String desc) { item=new Item(); item.setDescription(desc); } public static void main(String[] args) { Item it=new Item(); it.setDescription("Gobstopper"); Item it2=new Item(); it2.setDescription("Fizzylifting"); it.modifyDesc(it,"Scrumdiddlyumptious"); System.out.println(it.getDescription()); System.out.println(it2.getDescription()); } }

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Given: public class Message { String msg; int noOfWords; public Message() { msg += " Thank you"; } public Message(int noOfWords) { this.noOfWords = noOfWords; msg = "Welcome"; Message(); } public static void main(String args[]) { Message m = new Message(5); System.out.println(m.msg); } } What will be the output ?

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Predict the output. public class Test { public static void main(String args[]) { int a = 2, b = 0; for ( ; b < 20; ++b) { if (b % a == 0) continue; else if (b == 10) break; else System.out.print(b + " "); } } }

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What will be the output of the following code? int i=20; if(i>10) { System.out.println( "The value of i is "+i); i++; if(i%2!=0) break; }

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switch(a) { default: System.out.println("Welcome"); } Of which data types can the variable a be? 1. long 2. byte 3. int 4. char 5. float 6. short

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class Sample{ private double num = 100; private int square(int a){ return a*a; } } public class Test{ public static void main(String args[]){ Sample obj = new Sample(); System.out.println(obj.num); System.out.println(obj.square(10)); } }

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Choose the appropriate access specifier for the attribute value so that it can be accessed from anywhere. class Test { public int value; }

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Consider the below code snippet and determine the output. class Student { private int studentId; private float average; } class Test { public static void main(String a[]) { Student s=new Student(); s.studentId=123; System.out.println(s.studentId); } }

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The below code snippet shows an error cannot find symbol: System.out.println("BookId:"+bobj.getId()); public class Book { private int bookId; private double bookPrice; public int getBookId() { return bookId; } public void setBookId(int bookId) { this.bookId = bookId; } public double getBookPrice() { return bookPrice; } public void setBookPrice(double bookPrice) { this.bookPrice = bookPrice; } } public class Test { public static void main(String[] args) { Book bobj=new Book(); bobj.setBookId(123); bobj.setBookPrice(500); (" " ()) System.out.println("BookId:"+bobj.getId()); System.out.println("BookPrice:"+bobj.getBookPrice()); } } Analyze the above code and select the correct reason for the error.

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Observe the below code. public class Student { private int id; private String name; private char grade; //Constructor 1 public Student() { id=0; name= " "; } //Constructor 2 public Student(int id, String name) { this.id=id; this.name=name; } } Choose the constructor that is invoked, when an object is created as shown below. new Student(); Constructor 1 new Student(54, "John"); Constructor 2

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Observe the code below. public class Student { int studentId; String name; char grade; public Student(int studentId, String name, float mark) { this.studentId = studentId; this.name=name; calculateGrade(mark); } public void calculateGrade(float mark){ if(mark>90) grade='A'; else grade='B'; } } For the code Student s = new Student(1,"Peter",95); What will be the output?

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Observe the below class. class Product{ int productId; String productName; Product { productId=0; productName= ; } Product(int id, String name) { //access Product() ---- Line 1 productId=id; productName=name; } } Identify the valid option which is used to invoke the no argument constructor, Product(), at Line 1.

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Given the class Book and Library in two different packages : 1. package model; 2. public class Book { 3. private static void countBook { } 4. } 1. package util; 2. public class Library { 3. public static void main(String[] args) { 4. // insert code here 5. } 6. } What is required at line 4 in class Library to use the countBook method of Book class?

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Choose the correct order of the Java code fragments: 1) public class Main, 2) import java.util.Scanner;, 3) {, 4) // Some code here, 5) }, 6) package test;

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Assume class Calculator in package p1 and CalculatorService class in package p2 as shown below. package p1; public class Calculator { __________ static void calculate(){ //some code here } } package p2; import p1.Calculator; public class CalculatorService { public void display(){ Calculator.calculate(); } } What can be the valid access specifier for the calculate method in Calculator class so that it can be accessed from CalculatorService class?

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For the below code, what are the valid ways to invoke display method in the main method. public class Test { public static void display(){ } } public class Main { public static void main(String a[]){ //Invoke the display method } }

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What is the output of this program? class Output { public static void main(String args[]) { int a1[] = new int[10]; int a2[] = {1, 2, 3, 4, 5}; System.out.println(a1.length + " " + a2.length); } }

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class ArrayTest { public static void main(String args[]) { int[] primes = new int[10]; primes[0] = "a"; System.out.println(primes[0]); } } What will be the result of compiling and executing the above code?

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class TestArray { public static void main(String args[]) { int arr_sample[] = new int[2]; System.out.println(arr_sample[0]); } } What will be the result of compiling and executing the above code?

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Given: public class ItemTest { private final int id; public ItemTest(int id) { this.id = id; } public void updateId(int newId) { id = newId; } public static void main(String[] args) { ItemTest fa = new ItemTest(42); fa.updateId(69); System.out.println(fa.id); } } What is the result?

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Predict the Output of following Java Program. class Test { int x = 10; public static void main(String[] args) { System.out.println(x); } }

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package edu.ABC.model; public class Account { public static final float INTERTEST_RATE = 7.5; } Identify the correct options from the classes provided below.

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class Output { public static void main(String args[]) { int a1[] = new int[10]; int a2[] = {1, 2, 3, 4, 5}; System.out.println(a1.length + " " + a2.length); } }

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Predict the output p class String_demo { public static void main(String args[]) { int ascii[] = { 65, 66, 67, 68}; String s = new String(ascii, 1, 3); System.out.println(s); } }

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Determine the output: class Evaluate { public static void main(String args[]) { int arr[] = new int[] {0 , 1, 2, 3, 4, 5, 6, 7, 8, 9}; int n = 6; n = arr[arr[n] / 2]; System.out.println(arr[n] / 2); } }

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Predict the output class String_demo { public static void main(String args[]) { char chars[] = {'a', 'b', 'c'}; String s = new String(chars); System.out.println(s); } }

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Determine the output: (MCQ) public class Test { public static void main(String[] args) { int[] x = new int[3]; System.out.println("x[0]is"+x[0]); Sys e .ou .p ( [ ] s [ ]); } }

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Given: 1. public class MyLogger { 2. private StringBuilder logger = new StringBuuilder(); 3. public void log(String message, String user) { 4. logger.append(message); 5. logger.append(user); 6. } 7. } The programmer must guarantee that a single MyLogger object works properly for a multi-threaded system. How must this code be changed to be thread-safe?

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Determine the output: public class Test { public static void main(String[] args) { int[] x = {1, 2, 3, 4}; int[] y = x; x = new int[2]; for(int i = 0; i < x.length; i++) System.out.print(y[i] + " "); } }

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What will be the content of array variable table after executing the following code? public class Trial { public static void main(String[] args) { int []table[]=new int[5][5]; for(int i = 0; i < 3; i++) { for(int j = 0; j < 3; j++) { if(j == i) { table[i][j] = 1; System.out.print(table[i][j]); } else { table[i][j] = 0; System.out.print(table[i][j]); } } System.out.println("\n"); } } }

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Determine the output class array_output { public static void main(String args[]) { char array_variable [] = new char[10]; for (int i = 0; i < 10; ++i) { array_variable[i] = 'i'; System.out.print(array_variable[i] + ""); } } }

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Determine the output public class Trial { public static void main(String[] args) { int arr[4]={}; System.out.print(arr[0]); } }

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Determine the output: public class A { public static void main(String argv[]) { int ary[]=new int[]{1,2,3}; System.out.println(ary[1]); } }

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Predict the output of the below code : import java.util.regex.*; public class TestRegEx{ public static void main(String args[]) { Pattern p = Pattern.compile(".ech"); Matcher m = p.matcher("tech"); boolean b = m.matches(); System.out.println(b); } }