OCAJP7

Which of the following is illegal:

public class Test { static int age; public static void main (String args []) { age = age + 1; System.out.println("The age is " + age); } }

public static void main(String[] args) { int age; System.out.println(age+1); }

Which of the following return true?

Which of the following is correct:

Compiler adds default constructor to class which hasn't got constructor with empty argument list. Is it true?

Which of the following are acceptable to the Java 7 compiler?

Assuming a method contains code which may raise an Exception (but not a Runtime Exception), what is the correct way for a method to indicate that it expects the caller to handle that exception:

Czy w jednym konstruktorze można wywołać inny konstruktor z tej samej klasy i konstruktor z klasy bazowej jednocześnie?

Which variables can an inner class access from the class which encapsulates it?

In the following code, which is the earliest statement, where the object originally held in e, may be garbage collected: 1. public class Test { 2. public static void main (String args []) { 3. Employee e = new Employee("Bob", 48); 4. e.calculatePay(); 5. System.out.println(e.printDetails()); 6. e = null; 7. e = new Employee("Denise", 36); 8. e.calculatePay(); 9. System.out.println(e.printDetails()); 10. } 11. }

Given the following code what is the effect of a being 5: public class Test { public void add(int a) { loop: for (int i = 1; i < 3; i++){ for (int j = 1; j < 3; j++) { if (a == 5) { break loop; } System.out.println(i * j); } } } }

What is the result of executing the following fragment of code: boolean flag = false; if (flag = true) { System.out.println("true"); } else { System.out.println("false"); } }

What will be the output of the program? public class Foo { public static void main(String[] args) { try { return; } finally { System.out.println( "Finally" ); } } }

Which of the following are correct. Select the one correct answer.

Select the one correct answer. Which method defined in Integer class can be used to convert an Integer object to primitive int type.

Which code determines the int value data closer to, but not greater than, a double value b?

Which statement is true for the Class java.util.HashSet?

What will be the output of the program? public class X { public static void main(String [] args) { try { badMethod(); System.out.print("A"); } catch (Exception ex) { System.out.print("B"); } finally { System.out.print("C"); } System.out.print("D"); } public static void badMethod() { throw new Error(); /* Line 22 */ } }

What is valid returnType for getData? public Class returnData { <returnType> getData(byte a, double z) { return (short)a/z * 10; } }

What is the result? int index = 1; Boolean [] test = new Boolean[3]; Boolean data = test[index];

What will be the output of the program? class A { final public int GetResult(int a, int b) { return 0; } } class B extends A { public int GetResult(int a, int b) {return 1; } } public class Test { public static void main(String args[]) { B b = new B(); System.out.println("x = " + b.GetResult(0, 1)); } }

class SC2 { public static void main(String [] args) { SC2 s = new SC2(); s.start(); } void start() { int a = 3; int b = 4; System.out.print(" " + 7 + 2 + " "); System.out.print(a + b); System.out.print(" " + a + b + " "); System.out.print(foo() + a + b + " "); System.out.println(a + b + foo()); } String foo() { return "foo"; } }

Float f = new Float("12"); switch (f) { case 12: System.out.println("Twelve"); case 0: System.out.println("Zero"); default: System.out.println("Default"); }

Which statement is true for the class java.util.ArrayList?

public class Test { public void foo() { assert false; /* Line 5 */ assert false; /* Line 6 */ } public void bar() { while(true) { assert false; /* Line 12 */ } assert false; /* Line 14 */ } }

What will be the output of the program? public class Test138 { public static void stringReplace (String text) { text = text.replace ('j' , 'c'); /* Line 5 */ } public static void bufferReplace (StringBuffer text) { text = text.append ("c"); /* Line 9 */ } public static void main (String args[]) { String textString = new String ("java"); StringBuffer textBuffer = new StringBuffer ("java"); /* Line 14 */ stringReplace(textString); bufferReplace(textBuffer); System.out.println (textString + textBuffer); } }

Which declaration of the main method below would allow a class to be started as a standalone program.

Which of these are legal array declarations or definitions?

Which of the following are keywords in Java.

Which of these are legal identifiers.

The class Hashtable is used to implement which collection interface.

TreeMap class is used to implement which collection interface. Select the one correct answer.

What gets displayed on the screen when the following program is compiled and run. protected class example { public static void main(String args[]) { String test = "abc"; test = test + test; System.out.println(test); } }

class xyz { static int i; public static void main(String args[]) { while (i < 0) { i--; } System.out.println(i); } }

What gets printed on the standard output when the class below is compiled and executed. class A { boolean b = true, f; private void testujemy() { int i = 0; boolean t = true; b = (t || ((i++) == 0)); b = (f || ((i+=2) > 0)); System.out.println(i); } }

A class can have many methods with the same name as long as the number of parameters or type of parameters is different. This OOP concept is known as

Using up to four characters what is the Java representation of the number 23 in hex?

What are the two parts of a value of type double?

Using up to four characters, write the Java representation of integer literal 3 in hexadecimal.

What gets printed when the following program is compiled and run. Select the one correct answer. public class test { public static void main(String args[]) { byte x = 3; x = (byte)~x; System.out.println(x); } }

Java endianness is:

What gets displayed on the screen when the following program is compiled and run. Select the one correct answer. public class test { public static void main(String args[]) { int x,y; x = 3 & 5; y = 3 | 5; System.out.println(x + " " + y); } }

What will be the output of code: switch(3) { case 3: continue; case 4: System.out.println("Case 3 and 4"); break; case 5: System.out.println("Case 5"); }

In switch statement the default case must be at the end of switch body.

Given two non-negative integers a and b and a String str, what is the number of characters in the expression str.substring(a,b) . Select the one correct answer.

All the wrapper classes (Integer, Boolean, Float, Short, Long, Double and Character) in java are

Consider the following code snippet. What will be assigned to the variable fourthChar, if the code is executed? String str = new String("Java"); char fourthChar = str.charAt(4);