trophyChallenge - 5 Problems

🎖️

String Creation Master

Get all challenges correct to earn this badge!

Test your skills under time pressure!

💻 code output

intermediate

2:00remaining

What is the output of this Java code?

Consider the following Java code snippet:

String s1 = "hello";
String s2 = new String("hello");
System.out.println(s1 == s2);

What will be printed?

Java

String s1 = "hello";
String s2 = new String("hello");
System.out.println(s1 == s2);

Afalse

Btrue

CCompilation error

DRuntime exception

Attempts:

2 left

💻 code output

intermediate

2:00remaining

What is the output of this Java code using StringBuilder?

Look at this code:

StringBuilder sb = new StringBuilder("abc");
sb.append("def");
System.out.println(sb.toString());

What will be printed?

Java

StringBuilder sb = new StringBuilder("abc");
sb.append("def");
System.out.println(sb.toString());

Aabc def

Babcdef

Cabc

DCompilation error

Attempts:

2 left

🔧 debug

advanced

2:00remaining

What error does this code raise?

Examine this Java code snippet:

String s = null;
int length = s.length();
System.out.println(length);

What error will this code cause when run?

Java

String s = null;
int length = s.length();
System.out.println(length);

ANullPointerException

BCompilation error

CArrayIndexOutOfBoundsException

DNo error, prints 0

Attempts:

2 left

💻 code output

advanced

2:00remaining

What is the output of this code using String intern()?

Consider this Java code:

String s1 = new String("test");
String s2 = s1.intern();
String s3 = "test";
System.out.println(s2 == s3);

What will be printed?

Java

String s1 = new String("test");
String s2 = s1.intern();
String s3 = "test";
System.out.println(s2 == s3);

ACompilation error

Bfalse

CRuntime exception

Dtrue

Attempts:

2 left

🧠 conceptual

expert

2:00remaining

How many String objects are created here?

Analyze this Java code snippet:

String s = "a" + "b" + new String("c");

How many distinct String objects are created at runtime?

Attempts:

2 left