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Quiz Questions for APCSA Unit 2
Quiz Questions and Code Cells for APCSA Unit 2
Unit 2: Using Objects Quiz
Question 1
Which method can be used to convert a string to lowercase in Java?
a) toLowerCase()
b) lower()
c) toLower()
d) toLowerCase(String str)
Answer: a) toLowerCase()
// Hack Q1,1: comment code (focus on Primitives, Arrays, Objects, and Methods)
// Hack Q1,2: make a class with main method to test all the failure cases
String[] arr1 = {"a", "b", "c", "d"};
String[] arr2 = {"A", "B", "C", "D"};
String msg = "The arrays are equal";
if (arr1.length != arr2.length) {
msg = "The arrays are not uniform";
} else {
for (int i = 0; i < arr1.length; i++) {
if (!arr1[i].toLowerCase().equals(arr2[i].toLowerCase())) {
msg = "The arrays contain differences in elements";
break;
}
}
}
System.out.println(msg);
Question 2
What is the output of the following code?
String s = "Hello World!";
System.out.println(s.length());
a) 11
b) 12
c) 13
d) 10
Answer:
// Answer Q2
// Hack: Prove it with code
Question 3
Which of the following is a correct way to create an instance of the String class?
a) String s = 'Hello';
b) String s = new String("Hello");
c) String s = String("Hello");
d) String s = Hello;
Answer:
// Answer Q3, be careful with answer
// Hack: Prove it with code