Overview of Java data types, variables, and arrays,

Category : Java | Sub Category : Data type, Variable and Arays | By Prasad Bonam Last updated: 2023-08-15 12:28:33 Viewed : 291

an overview of Java data types, variables, and arrays, along with examples and outputs.

1. Java Data Types:

Java has two categories of data types: primitive data types and reference data types.

Primitive Data Types: These are the basic building blocks for storing simple values.

• byte: 8-bit signed integer
• short: 16-bit signed integer
• int: 32-bit signed integer
• long: 64-bit signed integer
• float: 32-bit floating-point
• double: 64-bit floating-point
• char: 16-bit Unicode character
• boolean: Represents true or false

Reference Data Types: These include objects, arrays, and other user-defined types.

2. Variables:

Variables are named memory locations used to store values of different data types.

Syntax for declaring a variable:

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data_type variable_name;

Examples:

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int age;
double salary;
char initial;
boolean isActive;

3. Arrays:

Arrays are used to store multiple values of the same data type in a single variable. Arrays have a fixed size when they are created.

Syntax for declaring an array:

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data_type[] array_name = new data_type[array_size];

Examples:

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int[] numbers = new int[5];
double[] prices = new double[10];
String[] names = new String[3];

Here are some examples and outputs to demonstrate these concepts:

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public class DataTypesVariablesArraysExample {
    public static void main(String[] args) {
        // Primitive Data Types
        int age = 25;
        double height = 170.5;
        char grade = `A`
        boolean isActive = true;
        
        System.out.println("Age: " + age);
        System.out.println("Height: " + height);
        System.out.println("Grade: " + grade);
        System.out.println("Is Active: " + isActive);
        
        // Arrays
        int[] numbers = new int[5];
        numbers[0] = 10;
        numbers[1] = 20;
        numbers[2] = 30;
        numbers[3] = 40;
        numbers[4] = 50;
        
        System.out.println("Array elements:");
        for (int i = 0; i < numbers.length; i++) {
            System.out.println(numbers[i]);
        }
        
        // Reference Data Types
        String name = "John Doe";
        System.out.println("Name: " + name);
    }
}

Output:

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Age: 25
Height: 170.5
Grade: A
Is Active: true
Array elements:
10
20
30
40
50
Name: John Doe

In this example, we have covered primitive data types, variables, and arrays. We have declared variables of different data types, initialized an array, and printed their values. The output showcases the values stored in the variables and the array.