ITB 102-(Computer Programming 1)

Java

• is a popular programming language created in 1995.

• it is owned by Oracle, and more than 3 bilion devices run using this language.

Java Syntax

the name of the java file must be match the class name. When saving the file, saveit using the class name and add “.java” at the end.

Main Method

is required and you will see it in every Java Programming. Any code inside this will be executed.

System.out.print()

inside the main() method, we can use this method to print a line if text to the screen

Double Quotes

when your working with a text, it must be wrapped around with “ “.

Print() Method

this also a print() method which is similar to println(). the only difference is that it does not insert a new line at the end of the output

Print Numbers

you can also use println() method to print numbers. However, unlike text, we don't put it inside “ “.

Java Variable

string, int, float, char, boolean

String

store texts

int

store integers

float()

stores floating point numbers

char()

store a single character

boolean()

stores a value with two states: true or false

Identifiers

all java Variable must be identified with unique names. These unique names are called ____.

Primitive and Non-Primitive Data Type

Data Types

byte, short, int, long, float, double, boolean, and char.

Variables under Primitive Data Type

String, Array, Classes

Variables under Non-Primitive Data Type

• Yes / No

• On / Off

• True / False

Boolean Type

Non-Primitive Data Type

are called reference type because they refer to objects.

Addition, Subtraction, Multiplication, Division, Modulus, Increment, Decrement

Arithmetic Operators

+

Operation for Addition

*

Operation for Multiplication

/

Operation for Division

%

Operation for Modulus

++

Operation for Increment

- -

Operation for Decrement

Single-Line Comment

starts with the forward dash ( // )

Multiple - Line Comments

starts with ( /* ) and ends with ( /* )

Java Operators

are used to perform operation on variables and values

Arithmetic Operators

Are use to perform common mathematical equations

Assignment Operators

are use to assign values to a variables

Comparison Operation

are used to compare values ( or variables )

Logical Operators

are use to determine the logic between variables and value

Java String

a variable contains a collection of characters surrounded by double quotes.

String Length

in java, is actually an object which contains method that can perform certain operations onnstrings

More String Method

there are many string methods available for example : toUpper() and toLower()