CS402 T04

1. What is the correct way to define a character in Java?

• char c = "A";

• char c = 'A';

• char c = A;

• char c = 'AB';

2. What will be the output of the following code?

char c = 65;

System.out.println(c);

• A

• 65

• Compilation Error

• Null

3. What does System.out.println('\\'); print?

• /

• \

• \\

• Compilation Error

4. How do you find the length of a string str in Java?

• str.size()

• str.length

• str.length()

• str.len()

5. What happens if you try to access an index outside a string's length using charAt()?

• Returns null

• Returns '0'

• Error, throws StringIndexOutOfBoundsException

• Returns ' '

6. Which method converts a string to uppercase in Java?

• str.toUpper()

• str.upper()

• str.toUpperCase()

• toUpperCase(str)

7. What does Math.random() return?

• A random int value

• A random value between 1.0 and 10.0

• A random double value greater than 1.0

• A random value between 0.0 and smaller than 1.0

8. How can you concatenate two strings, s1 and s2, in Java?

• s1 & s2

• concat(s1, s2)

• s1 | s2

• s1.concat(s2)

9. What is the output of Math.round(-2.6)?

• -3

• -2

• 3

• -2.0

10. What is the purpose of the trim() method in a string?

• Removes all characters from a string

• Removes whitespace from both ends of the string

• Converts a string to lowercase

• Removes the first and last characters of a string