Java Syntax

Quick Index

Syntax
English
Java
Context

In a given language, the syntax is the way the language elements (e.g. words) are put together. The "rules" of the language. Let us look at examples.

English

English Syntax:

Go to the game.
Let us drive there.

English Syntax Errors:

Gooooo to the game -- syntax error -- typo
Let there -- syntax error -- missing words

Java

Syntax has a similar meaning in Java.

Java Syntax:

public class Student
this.println("Hello Universe")

Java Syntax Errors:

public classssssss Student -- syntax error -- typo
this->println("Hello Universe") -- syntax error -- not a statement (->)

Fortunately, the Java compiler alerts us of syntax errors, allowing us to fix them before trying to run the program. This prevents the program from "blowing up" (i.e. "crashing").

Context

In programming, context means the "environment" that a given piece of programming "code" is running in.

Always know "where you are" (your context) when programming a piece of code.

Let us look at examples.

We have talked a lot about these two classes:

Student
	instance variables:
		firstName
		lastName
	
Rectangle
	instance variables:
		width
		height

So let us say we have constructed a Student object like this:

	a Student
		firstName = Yaping
		lastName = Deng

Example #1

Assume that we are "coding" (programming) in the Student class.

Can our "program code" use the firstName variable (defined in Student)?
Can our "program code" use the width variable (defined in Rectangle)?

Description

"Context" will help us answer these questions. Tips

Hints

Solution

Introduction To Objects With Java (Chapter 304 - Variables)

Chapter 304 - Variables Java Syntax

Chapter Contents Overview Naming Syntax Declaring Ivars Example Challenge

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