Unit 1: Introduction Lesson 1: PArts of a java program

Keywords Keywords have special meaning and are part of the Java programming language. They may not be used for anything other than their intended purpose.

OPERATORS Operators are symbols or words which perform operations (mathematical, logical etc.) on a piece of data. A piece of data which an operator acts on is called an Operand. Words that act as operators usually begin with a period.

Punctuation Punctuation characters are symbols which mark the beginning or end of statements. Punctuation characters may also be used to separate data items on a list.

Programmer defined words Programmer Defined Words are words that are defined by the programmer. The programmer chooses the purpose, and name of programmer defined words. Similar to Key Words, once the programmer defines the words and their purpose, the words may not be used in any other way.

Syntax Syntax are rules for how key words, operators punctuation, and user defined words may be used. Any use of key words, operators, punctuation or user defined words which is not in accordance with Syntax will result in an error.

Variables Variables are the most basic way in which a Java program stores information. Variable names are user defined. There are several types of variable, each type can only store a certain type of data. Variables can only store one item of data at a time, if the program stores another value, it will replace the original value.

The Compiler When a Program is written, the computer cannot immediately execute that code. It must first be converted from the Java programming language to a form that is readable by the computer's CPU. The Compiler is responsible for this conversion.

Integrated Development Environment An IDE is an application which bundles together a compiler, a text editor and a debugger. IDEs are commonly used to write programs, check for errors, compile, and execute the program. Some common IDEs are "Dr.Java", "JCreator" and "Eclipse"