CIT 260 Chapter 1

compiler

A compiler translates the entire source code into a machine-code file, and the machine-code file is then executed, as shown in the following figure.

blocks

A pair of braces in a program forms a block that groups components of a program. Ex: {} states the beginning and ending of a block

statements

A statement represents an action or a sequence of actions. The statement System.out.println("Welcome to Java!") in the program in Listing 1.1 is a statement to display the greeting "Welcome to Java!".

high-level language

Are English like and easy to learn and program. For example, the following is a high level language statement that computes the area of a circle with rradius 5 Area = 5 * 5 * 3.1415

classes

Every Java program must have at least one class. Each class has a name.

main

In order to run a class, the class must contain a method named main. The program is executed from the main method.

methods

In order to run a class, the class must contain a method named main. The program is executed from the main method.

IDE

Intergrated development envirorment Examples: Netbeans and eclipse

machine language

Is a set of primitive instructions built into every computer. The instructions are in the form of binary code, so you have to enter binary codes for various instructions. Programming with native machine language is a tedious process. Moreover the programs are highly difficult to read and modify. For example, to add two numbers, you might write an instruction in binary like this 1101101010011010

comments

It's a reference to what the code is doing or what it is. // and /* */ is how you comment What the program is who wrote it.

JDK

Java Development Kit: Tool to write java code

JVM

Java Virtual Machine is a software that interprets Java bytecode.

Java

Java is a general purpose programming language. Java is the Internet programming language.

modifiers

Modifiers are keywords that you add to those definitions to change their meanings.

reserved words

Reserved words or keywords are words that have a specific meaning to the compiler and cannot be used for other purposes in the program. For example, when the compiler sees the word class, it understands that the word after class is the name for the class.

assembly language

Were developed to make programming easy. Since the computer cannot understand assembly language, however, a program called assembler is used to convert assembly language programs into machine code. For example, to add two numbers, you might write an instruction in assembly code like addf3 r1, r2, r3

byte code

With Java, you write the program once, and compile the source program into a special type of object code, known as bytecode. The bytecode can then run on any computer with a Java Virtual Machine