Module 6 quiz on Object Oriented Programing concepts :Java for Android (Android App Development Specialization) Answers 2025

1. Question 1 – An object is

• ✔️ The grouping together of data and behavior to create a single entity

• ❌ The blue print for creating classes

• ❌ A way to hide implementation details from the user

• ❌ A sequence of characters

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2. Question 2 – A typical object-oriented program

• ✔️ uses objects to perform most of its useful behavior.

• ❌ uses objects to model ints, chars, booleans

• ❌ must consist of at least four classes

• ❌ uses methods and primitive data types to perform most behavior

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3. Question 3 – Example of abstraction

• ✔️ supplying a Quick Start guide with a digital camera.

• ❌ only selling to experienced users

• ❌ supplying technical drawings

• ❌ supplying batteries

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4. Question 4 – Instance of the City class

• ✔️ the city of Philadelphia.

• ❌ the plans for a city

• ❌ the methods

• ❌ the variables

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5. Question 5 – A class file is (select all that apply)

• ❌ a file containing a single program or module

• ✔️ a template or blueprint for an object

• ❌ a collection of objects

• ❌ a collection of keywords

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6. Question 6 – A String object is (select all that apply)

• ❌ a primitive data type

• ✔️ a reference to a memory location where data is stored

• ✔️ a sequence of characters

• ✔️ similar to primitive data types in some respects

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7. Question 7 – Statements that compile

• ❌ out.println(str1.concat(18.9)); (double not allowed in concat)

• ❌ out.println("Hello kids" - "kids");

• ✔️ out.println("Hello" + " programmers!");

• ✔️ out.println(str1 == str2); (compiles, even if logic is wrong)

• ✔️ out.println(str1.equals(str2));

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8. Question 8 – Create the string “herald”

Correct option:

• ✔️ str2 = str1.substring(0,2); str2 = str2 + "ra"; str2 = str2.concat(str1.substring(2,4));

Other options do not produce “herald” correctly.

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