Java Quick Intro

A rapid reference guide for syntax and concepts.

public class Main {
    public static void main(String args[]) {
        System.out.println("Hello World!");
    }
}

All input needs to be entered in the Input tab prior to compilation.

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import java.util.Scanner;
  
public class Main {
    public static void main(String args[]) {
        Scanner reader = new Scanner(System.in);  // Reading from System.in
        
        System.out.println("Enter name: ");
        String name = reader.nextLine(); // Scans the next token
        
        System.out.println("Enter age: ");
        int age = reader.nextInt(); // Scans the next token
        
        System.out.println(name + " is " + age + " years old.");
    }
}
int a = 10, b = 10;     // Example of initialization
double pi = 3.14159;    // declares and assigns a value of PI.
char c = 'a';
String d = "a string";
// For loop
for (int i = 0; i < 10; i++) {
    if (i % 2 == 0)
        System.out.println(i + " is an even number");
    else
        System.out.println(i + " is an odd number");
}

int[] numbers = {10, 20, 30, 40, 50};

// Fast enumeration
for (int x : numbers) {
    System.out.print(x + ",");
}

// Switch statement
String vegetable = "red pepper";
String vegetableComment;

switch (vegetable) {
    case "celery":  
        vegetableComment = "Add some raisins and make ants on a log.";
        break;
    case "cucumber":  
        vegetableComment = "That would make a good tea sandwich.";
        break;
    default: 
        vegetableComment = "Everything tastes good in soup.";
        break;
}
public class Main {
    public static void main(String args[]) {
        Employee empOne = new Employee("James Smith");
        empOne.empAge(26);
        empOne.empDesignation("Senior Software Engineer");
        empOne.empSalary(1000);
        empOne.printEmployee();
    }
}

class Employee {
    String name;
    int age;
    String designation;
    double salary;

    public Employee(String name) {
        this.name = name;
    }

    public void empAge(int empAge) {
        age = empAge;
    }

    public void empDesignation(String empDesig) {
        designation = empDesig;
    }
    
    public void empSalary(double empSalary) {
        salary = empSalary;
    }

    public void printEmployee() {
        System.out.println("Name:" + name);
        System.out.println("Age:" + age);
        System.out.println("Designation:" + designation);
        System.out.println("Salary:" + salary);
    }
}