0% completed

All LessonsFree Lessons (2)

A First Look at Java

Introduction: A First Look at Java The Programming Language Java A Simple Java Program Comments Data Types Variables Constants Simple Input from the Keyboard A Problem Solved: Apples by the Box Writing, Compiling, and Running a Java Program Summary: A First Look at Java Practice Challenges for Fun

Arithmetic Expressions

Introduction: Arithmetic Expressions Arithmetic Operators Conversions between Numeric Data Types A Problem Partially Solved: Day of the Week Standard Mathematical Methods A Problem Solved: Wind Chill Summary: Arithmetic Expressions Practice Challenges for Fun

Debugging Interlude—The Errors Programmers Make

Introduction: Debugging Interlude—the Errors Programmers Make Kinds of Errors Compile-Time Errors More Compile-Time Errors Execution-Time Errors Summary: Debugging Interlude—the Errors Programmers Make Practice Challenges for Fun

Using Classes and Objects

Introduction: Using Classes and Objects Terminology: Classes and Objects The Class String Methods of the Class String Strings and the Class Scanner A Problem Solved: Processing a String The Class LocalTime The Class BigDecimal Wrapper Classes The Class Random The Class DecimalFormat Summary: Using Classes and Objects Practice Challenges for Fun

Class Definitions—The Fundamentals

Introduction: Class Definitions—the Fundamentals Using a Class Beginning a Class Definition Defining Constructors Defining a Class’s Methods Local Variables Designing a New Class Implementing a New Class Passing Arguments A Problem Solved: Comparing Classes of Squares Summary: Class Definitions—the Fundamentals Practice Challenges for Fun

Debugging Interlude—Common Mistakes with Classes

Introduction: Debugging Interlude—Common Mistakes with Classes A Silent Computational Error Undefined Variables of a Class Type Constructors Omitting the Method toString A Problem Solved: Extracting Strings Summary: Debugging Interlude—Common Mistakes with Classes Practice Challenges for Fun

Decisions

Introduction: Decisions The if Statement Basic Comparisons A Problem Solved: Day of the Week The if-else Statement More Boolean Expressions in Comparisons A Problem Solved: Leap Years Assertions Summary: Decisions Practice Challenges for Fun

Class Definitions—More Details

Introduction: Class Definitions—More Details Boolean-Valued Methods Private Methods Final Fields and Static Fields Enumerations A Problem Solved: Representing Coins Completing the Definition of the Class Coin Calling a Constructor from a Constructor Summary: Class Definitions—More Details Practice Challenges for Fun

Multiway Decisions

Introduction: Multiway Decisions Nested if Statements More Examples of Multiway if Statements A Problem Solved: Health Club Welcome The switch Statement More Examples of the switch Statement A Problem Solved: Designing a Class of Temperatures A Problem Solved: Defining the Class Temperature Summary: Multiway Decisions Practice Challenges for Fun

Debugging Interlude—Avoiding Mistakes; Finding Mistakes

Introduction: Debugging Interlude—Avoiding/Finding Mistakes Avoiding Mistakes Debugging a Program in Development An Introduction to Testing Refining a Problem’s Solution Summary: Debugging Interlude—Avoiding/Finding Mistakes

Repetition

Introduction: Repetition

The Logic of a Loop

The while Statement

A Problem Solved: A Guessing Game

Mistakes in Loops

Boolean Variables in Loops

The Scope of a Variable

A Problem Solved: The Root of an Equation

Summary: Repetition

Practice Challenges for Fun

Repetition Continued

Introduction: Repetition Continued The for Statement More Examples Using an Enumeration with a for Statement The do Statement Summary: Repetition Continued Practice Challenges for Fun

Debugging Interlude—Debugging Loops

Introduction: Debugging Interlude—Debugging Loops Testing Tracing An Example: String Processing Overview of Debugging Tools Summary: Debugging Interlude—Debugging Loops

Arrays

Introduction: Arrays Motivation Array Basics More Array Basics A Problem Solved—Computing Deviations Partially Filled Arrays Counting Occurrences in an Array Locating the Smallest Entry in an Array Searching an Array for a Given Entry Arrays of Objects Arrays as Arguments or Return Values in a Method Array Assignments Copying an Array Array Equality Summary: Arrays Practice Challenges for Fun Copying an ArrayProofer version

An Array-Based Data Structure

Introduction: An Array-Based Data Structure The Data Collection Bag Specifying a Bag Identifying a Group of Core Methods Defining the Data Fields, Constructors, and Core Methods The Class BagOfStrings So Far Implementing More Methods Methods That Remove Strings The Methods getIndexOf and contains Testing the Methods That Remove Strings Testing the Completed Class BagOfStrings Summary: An Array-Based Data Structure Practice Challenges for Fun

Debugging Interlude—Debugging Arrays

Introduction: Debugging Interlude—Debugging Arrays An Unallocated Array A Silent Error Array Index Out of Bounds Summary: Debugging Interlude—Debugging Arrays

Glossary

Glossary of Terms

Appendixes

Introduction to Computing Reserved Words Unicode Characters Documentation and Programming Style Java Programming After this Course Getting Java for Free

Copyright

Java Masterclass for Software Developers/

...

/

Nested Loops

Nested Loops

In this lesson, we will look at nesting a loop within the body of another one.

We'll cover the following...

Problem statement

Imagine that we want to display a square pattern of stars (asterisks), such as:

* * * *
* * * *
* * * *
* * * *

where the number of rows and the number of stars per row are the same. This number is essentially the length of the side of the square. However, we might not know this length in advance. If we ask the user for this value—call it n—we need a loop to display n stars in one row. We need ...