Core Java Data Types, Variables, and Operators

Data types, variables, and operators

Understanding data types helps you store different kinds of information in your programs. Variables are containers for storing data, while operators perform actions on data.

Examples

public class Examples {
    public static void main(String[] args) {
        // Example 1: Using variables to store numbers
        int x = 10;
        int y = 20;
        int sum = x + y;
        System.out.println("Sum of x and y: " + sum);

        // Example 2: Combining strings using concatenation
        String firstName = "John";
        String lastName = "Doe";
        String fullName = firstName + " " + lastName;
        System.out.println("Full Name: " + fullName);

        // Example 3: Using comparison operators to compare values
        int a = 5;
        int b = 10;
        boolean result = (a > b); // false
        System.out.println("Is a greater than b? " + result);
    }
}

FAQ (interview questions and answers)

1. What is a variable in Java?
   A reserved word in Java
   A container for storing data
   A type of loop in Java
   
2. What are data types?
   Types of values that can be stored in variables
   Variables that store only numeric values
   Data stored in files
   
3. What do operators do in Java?
   Perform actions on data
   Store data in variables
   Create new variables
   
4. What is the purpose of using variables?
   To print output to the console
   To execute Java code
   To store and manipulate data
   
5. How can you combine strings in Java?
   Using comparison operators
   Using concatenation
   Using arithmetic operators
   

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