Summary of Session 17- Wrapper Classes | Data Conversion | Packages | Access Modifiers | 2024 New series

Summary of Video: "Session 17- Wrapper Classes | Data Conversion | Packages | Access Modifiers | 2024 New series"

Main Ideas and Concepts:

Wrapper Classes:
In Java, primitive data types (like int, float, etc.) can be converted into objects using Wrapper Classes (e.g., Integer for int, Double for Double).

Each primitive type has a corresponding wrapper class:
- int → Integer
- float → Float
- Double → Double
- Boolean → Boolean
- char → Character
Wrapper Classes are beneficial for:
- Creating object representations of primitive types.
- Data Conversion between different formats.
Data Conversion:
Conversion between string and numeric types is crucial for operations like addition.

Methods in Wrapper Classes facilitate conversion:
- Integer.parseInt(String s): Converts string to int.
- Double.parseDouble(String s): Converts string to Double.
- Boolean.parseBoolean(String s): Converts string to Boolean.
- Conversion from primitive types to string can be done using String.valueOf().
Important to handle exceptions when converting invalid strings to numeric types.
Packages:
Packages in Java are like folders that organize classes.

Two types of packages:
- Built-in Packages: Predefined by Java (e.g., java.util).
- User-Defined Packages: Created by the user.
Packages help maintain organized code and facilitate access to classes.
Access Modifiers:
Define the scope of variables and methods in Java.

Four types of Access Modifiers:
- Private: Accessible only within the same class.
- Default: Accessible within the same package (no keyword needed).
- Protected: Accessible within the same package and through inheritance in other packages.
- Public: Accessible from any other class in any package.
Understanding Access Modifiers is crucial for encapsulation and security in programming.

Methodology / Instructions:

Data Conversion:
To convert a string to an Integer:
```
int number = Integer.parseInt("123");
```
To convert an Integer to a string:
```
String str = String.valueOf(number);
```

Using Wrapper Classes:

Example of creating an Integer object:

Integer myInt = new Integer(100);

Converting string prices to numeric for addition:

String price1 = "150.50";
String price2 = "120.50";
Double totalPrice = Double.parseDouble(price1) + Double.parseDouble(price2);

Package Creation:
To create a package in Java:
```
package myPackageName;
```
Using Access Modifiers:
Declaring a variable as private:
```
private int myVar;
```
Declaring a method as public:
```
public void myMethod() {}
```

Speakers/Sources Featured:

The video appears to feature a single instructor who explains these concepts in detail, likely in a classroom or tutorial setting. The instructor is not named in the subtitles provided.

Notable Quotes

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