Javaoo 1-4 Chapter Study Focus

Data types in Java: base types, reference types

Basic types: Numeric type, byte type, shaping, long shaping, character type, Boolean type, etc.

Reference type: Class, interface, array;

Considerations for Using Identifiers:

1. Cannot start with a number

2. Case-sensitive

3. Cannot quote keywords

4. Hump naming Method (capital letter)

5. Pascal's nomenclature (first letter primary school, other words capitalized)

Application of π

π: Final data type constant name (all uppercase) = constant value

Input in Java

Header file:import Java.util.Scanner

public{

Scanner input (can be named) = new Scanner (system.in)

Input: System.out.println ("Please enter:");

int (data type) num (can be named) = Input.nextint ()

Input.nextint (); (receive shaping input)

Input.nextdouble (); (receive double type input)

Input.next (); (Receive string type input)

}

The minimum value of an integer in Java: integer. Min_value; (green part must be capitalized)

Random number in Java:(int) (Math.random () *100);

Strings in Java are compared equally:

Example: if ("Name". Equals (variable name))

Fully qualified name: Package name. class name. Fully qualified name

The package's reputation must be the first executable statement in the source file

Important Words: public protected protected private

Method: Public String toString () {

Return "name" +name+ "gender" +sex + "age" + Ages

}

Access modifier return value type method name (parameter list) {

Method Body: The function code block to be implemented

}

To create an object:

Example:

To create a student object:

Student stu = new Student ();

Stu. Variable name ();

Javaoo 1-4 Chapter Study Focus