Instruction
- Total number of questions : 30.
- Time alloted : 30 minutes.
- Each question carry 1 mark.
- No Negative marks
- DO NOT refresh the page.
- All the best :-).
1. |
What is the range of byte data type in Java? |
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Your Answer: Option (Not Answered) Correct Answer: Option A Explanation: Byte occupies 8 bits in memory. Its range is from -128 to 127. |
2. |
Which of these coding types is used for data type characters in Java? |
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Your Answer: Option (Not Answered) Correct Answer: Option C Explanation: Unicode defines fully international character set that can represent all the characters found in all human languages. Its range is from 0 to 65536. |
3. |
Which of these can be returned by the operator & ? |
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Your Answer: Option (Not Answered) Correct Answer: Option D Explanation: We can use binary ampersand operator on integers/chars (and it returns an integer) or on booleans (and it returns a boolean). |
4. |
What is the prototype of the default constructor of this class? |
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Your Answer: Option (Not Answered) Correct Answer: Option D Explanation: None. |
5. |
What is the output of this program? class array_output { public static void main(String args[]) { int array_variable[][] = {{ 1, 2, 3}, { 4 , 5, 6}, { 7, 8, 9}}; int sum = 0; for (int i = 0; i < 3; ++i) for (int j = 0; j < 3 ; ++j) sum = sum + array_variable[i][j]; System.out.print(sum / 5); } } |
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Your Answer: Option (Not Answered) Correct Answer: Option B Explanation: None. |
6. |
Modulus operator, %, can be applied to which of these? |
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Your Answer: Option (Not Answered) Correct Answer: Option C Explanation: Modulus operator can be applied to both integers and floating point numbers. . |
7. |
Which operator is used to invert all the digits in binary representation of a number? |
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Your Answer: Option (Not Answered) Correct Answer: Option A Explanation: Unary not operator, ~, inverts all of the bits of its operand in binary representation. |
8. |
Which of these is returned by “greater than”, “less than” and “equal to” operators? |
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Your Answer: Option (Not Answered) Correct Answer: Option C Explanation: All relational operators return a boolean value ie. true and false. |
9. |
What should be expression1 evaluate to in using ternary operator as in this line? |
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Your Answer: Option (Not Answered) Correct Answer: Option C Explanation: The controlling condition of ternary operator must evaluate to boolean. |
10. |
Which of these are selection statements in Java? |
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Your Answer: Option (Not Answered) Correct Answer: Option A Explanation: continue and break are jump statements, and for is an looping statement. |
11. |
Which of these keywords is used to make a class? |
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Your Answer: Option (Not Answered) Correct Answer: Option A Explanation: None. |
12. |
What is the process of defining more than one method in a class differentiated by method signature? |
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Your Answer: Option (Not Answered) Correct Answer: Option B Explanation: Function overloading is a process of defining more than one method in a class with same name differentiated by function signature i:e return type or parameters type and number. Example – int volume(int length, int width) & int volume(int length , int width , int height) can be used to calculate volume. |
13. |
Which keyword is used by method to refer to the object that invoked it? |
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Your Answer: Option (Not Answered) Correct Answer: Option D Explanation: this keyword can be used inside any method to refer to the current object. this is always a reference to the object on which the method was invoked. |
14. |
Which of these can be overloaded? |
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Your Answer: Option (Not Answered) Correct Answer: Option C Explanation: None. |
15. |
Which of these is used to access member of class before object of that class is created? |
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Your Answer: Option (Not Answered) Correct Answer: Option C Explanation: None. |
16. |
Which of these keywords is used to prevent content of a variable from being modified? |
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Your Answer: Option (Not Answered) Correct Answer: Option A Explanation: A variable can be declared final, doing so prevents its content from being modified. Final variables must be initialized when it is declared. |
17. |
Which of these method of String class is used to obtain character at specified index? |
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Your Answer: Option (Not Answered) Correct Answer: Option D Explanation: None. |
18. |
Which of these keywords is used to refer to member of base class from a sub class? |
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Your Answer: Option (Not Answered) Correct Answer: Option B Explanation: whenever a subclass needs to refer to its immediate superclass, it can do so by use of the keyword super. |
19. |
What is the process of defining a method in subclass having same name & type signature as a method in its superclass? |
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Your Answer: Option (Not Answered) Correct Answer: Option B Explanation: None. |
20. |
Which of these method of Object class can clone an object? |
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Your Answer: Option (Not Answered) Correct Answer: Option C Explanation: None. |
21. |
Which of these operators can be used to concatenate two or more String objects? |
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Your Answer: Option (Not Answered) Correct Answer: Option A Explanation: operator + is used to concatenate strings, Example String s = “i ” + “like ” + “java”; String s contains “I like java” |
22. |
Which of these methods is an alternative to getChars() that stores the characters in an array of bytes? |
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Your Answer: Option (Not Answered) Correct Answer: Option A Explanation: getBytes() stores the character in an array of bytes. It uses default character to byte conversions provided by platform. |
23. |
What will s2 contain after following lines of code? |
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Your Answer: Option (Not Answered) Correct Answer: Option C Explanation: Two strings can be concatenated by using concat() method. |
24. |
Which of these method of class StringBuffer is used to concatenate the string representation to the end of invoking string? |
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Your Answer: Option (Not Answered) Correct Answer: Option B Explanation: None. |
25. |
What will s2 contain after following lines of code? |
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Your Answer: Option (Not Answered) Correct Answer: Option C Explanation: Two strings can be concatenated by using append() method. |
26. |
Which of these methods is used to compare a specific region inside a string with another specific region in another string? |
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Your Answer: Option (Not Answered) Correct Answer: Option D Explanation: None. |
27. |
Which of these is a mechanism for naming and visibility control of a class and its content? |
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Your Answer: Option (Not Answered) Correct Answer: Option B Explanation: Packages are both naming and visibility control mechanism. We can define a class inside a package which is not accessible by code outside the package. |
28. |
Which of these can be used to fully abstract a class from its implementation? |
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Your Answer: Option (Not Answered) Correct Answer: Option C Explanation: None. |
29. |
Which of these is a process of converting a simple data type into a class? |
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Your Answer: Option (Not Answered) Correct Answer: Option A Explanation: None. |
30. |
Which of the following methods is a method of wrapper Integer for obtaining hash code for the invoking object? |
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Your Answer: Option (Not Answered) Correct Answer: Option C Explanation: None. |