SCJP Java String Handling and Regular Expressions 2

Question 1

What is the output of: System.out.println("Java".toUpperCase());

Accepted Answer

JAVA

Answer

java

Answer

Java

Answer

jAVA

Question 2

What does String.valueOf(42) return?

Accepted Answer

"42" as a String

Answer

42 as an int

Answer

42.0 as a double

Answer

A NullPointerException

Question 3

Which regular expression pattern matches one or more digits?

Accepted Answer

\d+

Answer

\d*

Answer

\d?

Answer

\d{0,}

Question 4

What is the result of "  Hello  ".trim()?

Accepted Answer

"Hello"

Answer

"  Hello  "

Answer

"Hello  "

Answer

"  Hello"

Question 5

Which method of the Pattern class is used to compile a regular expression?

Accepted Answer

Pattern.compile()

Answer

Pattern.create()

Answer

Pattern.build()

Answer

Pattern.match()

Question 6

What does the String method replace(char oldChar, char newChar) return?

Accepted Answer

A new String with all occurrences of oldChar replaced by newChar

Answer

It modifies the original String in place

Answer

Only the first occurrence replaced

Answer

A boolean indicating if replacement occurred

Question 7

What is the output of: System.out.println("hello".charAt(1));

Accepted Answer

e

Answer

h

Answer

l

Answer

1