Tag: programming languages

Questions Related to programming languages

1.Set s = new HashSet(); 2.s.add("JAVA"); 3.s.add(new Integer(5)); Line 3 will give ClassCast Exception because Two different types of object are getting added.

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  1. True

  2. False

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Correct Option: B

Which of the following is not a reserved keywords?
technology programming languages

  1. public

  2. static

  3. void

  4. main

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Correct Option: D

What is the value of the expression (1 / 2 + 3 / 2 + 0.1)?
technology programming languages

  1. 1

  2. 1.1

  3. 1.6

  4. 2.1

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Correct Option: B

1.Set s = new TreeSet(); 2.s.add("JAVA"); 3.s.add(new Integer(5)); Line 3 will give ClassCast Exception because Two different types of object are getting added.

technology programming languages

  1. True

  2. False

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Correct Option: A

Which of the following operators can be used both as an integer bitwise operator and a boolean logical operator?
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  1. ^

  2. !

  3. &

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Correct Option: A,C,D

Which one of these is a valid method declaration?

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  1. void method1 { /* ... */ }

  2. void method2() { /* ... */ }

  3. void method3(void) { /* ... */ }

  4. method4() { /* ... */ }

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Correct Option: B

AI Explanation

To answer this question, you need to understand the syntax for declaring methods in a programming language. Let's go through each option to understand why it is correct or incorrect:

Option A) void method1 { /* ... */ } - This option is incorrect because it is missing the parentheses after the method name. The correct syntax for declaring a method includes the parentheses to enclose any parameters that the method may take.

Option B) void method2() { /* ... */ } - This option is correct because it follows the correct syntax for declaring a method. The method name is "method2" and it does not take any parameters, as indicated by the empty parentheses. The return type of the method is "void", indicating that the method does not return a value.

Option C) void method3(void) { /* ... */ } - This option is incorrect because it includes the keyword "void" as a parameter. In most programming languages, the "void" keyword is used only as the return type to indicate that the method does not return a value. It should not be used as a parameter.

Option D) method4() { /* ... */ } - This option is incorrect because it does not specify a return type for the method. In most programming languages, you need to specify the return type of a method, even if it is "void" to indicate that the method does not return a value.

The correct answer is B) void method2() { /* ... */ }. This option is correct because it follows the correct syntax for declaring a method and does not have any errors or missing components.

Any problem in generic code is handled at Runtime.
technology programming languages

  1. True

  2. False

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Correct Option: B

Which one of the following class definitions is a valid definition of a class that cannot be extended?
technology programming languages

  1. abstract class Link { }

  2. native class Link { }

  3. final class Link { }

  4. abstract final class Link { }

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Correct Option: C

Which of these combinations of switch expression types and case label value types are legal within a switch statement?
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  1. switch expression of type int and case label value of type char

  2. switch expression of type float and case label value of type int

  3. switch expression of type byte and case label value of type float

  4. switch expression of type char and case label value of type long

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Correct Option: A
Explanation:

To answer this question, the user needs to have an understanding of the Java switch statement syntax and the types of expressions and case labels that are allowed within it.

A switch statement allows a program to evaluate an expression and then execute one of several possible blocks of code, depending on the value of the expression. The expression and case labels must be of a compatible type. Compatible types are those that can be implicitly converted to each other without loss of information.

Now, let's go through each option and explain why it is right or wrong:

A. switch expression of type int and case label value of type char: This option is legal. The char type can be implicitly promoted to int, which means that a char can be used as a case label with an int expression.

B. switch expression of type float and case label value of type int: This option is illegal. The int type can't be implicitly converted to float, which means that an int cannot be used as a case label with a float expression.

C. switch expression of type byte and case label value of type float: This option is illegal. The float type can't be implicitly converted to byte, which means that a float cannot be used as a case label with a byte expression.

D. switch expression of type char and case label value of type long: This option is illegal. The long type can't be implicitly converted to char, which means that a long cannot be used as a case label with a char expression.

Therefore, the correct answer is:

The Answer is: A. switch expression of type int and case label value of type char

Which statements are true?
technology programming languages

  1. {{}} is a valid statement block

  2. { continue; } is a valid statement block

  3. block: { break block; } is a valid statement block

  4. block: { continue block; } is a valid statement block

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Correct Option: A,C