Skip to main content

Posts

Java Program to count number of employees working in a company (Completed With Garbage Collection)

    // Java Program to count number of employees working in a company (Completed With Garbage Collection)     class Employee {         private String name ;         private int age ;         private int ID ;         private static int nextId = 1 ;                         public Employee ( String name , int age ) {             this . name = name;             this . age = age;             this . ID = nextId ++ ;         }                 public void show ()         {             System . out . println ( " \n ID=" + ID +   " \n Name=" + name + " \n Age=" + age);         }                 public void showNextId ()         {             System . out . println ( "Next employee id will be=" + nextId);         }                 protected void finalize ()         {             -- nextId;             // In this case,             // gc will call finalize()             // for 2 times for 2 objects.         }     }     c
Recent posts

Mastering Python Decorators: A Comprehensive Guide

Welcome to our comprehensive guide on mastering Python decorators! Whether you're a seasoned Python developer or just starting your coding journey, understanding decorators is a key step toward writing more elegant and efficient code. What are Decorators? Decorators are a powerful feature in Python that allows you to modify the behavior of functions or methods. They provide a clean and concise way to enhance the functionality of your code without cluttering it with repetitive patterns. Basics of Decorators Let's start with the basics. In Python, decorators are denoted by the @decorator syntax . Consider the following example:          def my_decorator ( func ):         def wrapper ():             print ( "Something is happening before the function is called." )             func()             print ( "Something is happening after the function is called." )         return wrapper     @my_decorator     def say_hello ():         print ( "Hello!" )

How to find duplicate records in MongoDB?

To find duplicate entries in MongoDB based on the code and user_id fields, you can use the aggregate method along with the $group and $match pipeline stages. Here is an example of how to do this: Let's take the example collection - user_collection .     {             "_id" : ObjectId( "640054ef881f521a7b68fc96" ) ,             "code" : "google_uploader" ,             "user_id" : "33052" ,             "type" : "uploader" ,             "charge_type" : "Prepaid" ,             "available_credits" : 500 ,             "total_used_credits" : 0     }     {             "_id" : ObjectId( "640054ef881f521a7b68fc99" ) ,             "code" : "google_uploader" ,             "user_id" : "33052" ,             "type" : "uploader" ,             "charge_type" : "Prepaid&quo

How to copy one collection to another by adding a field in MongoDB?

Is there a way to copy one collection to another in MongoDB while adding a new field? Yes, it is possible to copy one collection to another in MongoDB by adding a field using the $addFields pipeline stage in the aggregation framework. Here is an example of how you can do it: Suppose we have two collections named source_collection and target_collection , and we want to copy data from source_collection to target_collection by adding a new field called new_field . Sample source_collection documents:     {         "_id" : 1 ,         "name" : "John" ,         "age" : 25     },     {         "_id" : 2 ,         "name" : "Jane" ,         "age" : 30     },     {         "_id" : 3 ,         "name" : "Bob" ,         "age" : 40     } We want to copy this collection to a new collection named target_collection by adding a new field new_field which contains a string value. T

How to perform CRUD operations using Node.js and MongoDB?

CRUD with Node.js and MongoDB To perform CRUD (Create, Read, Update, and Delete) operations using Node.js and MongoDB, we can follow these steps: 1. Install Node.js To install Node.js, visit https://nodejs.org/en/ . The node version used in this code is v16.15.0. 2. Install the MongoDB driver First, create a project directory. We will name our project "CrudApp" . Then, to install the MongoDB driver, use npm by running the following command: npm install mongodb For the database view, you can download MongoDB Compass, or MongoDB Atlas can also be used. 3. It's time to CODE          // Node.js has a built-in module called HTTP. This helps     // Node.js to send information using the     // Hyper Text Transfer Protocol (HTTP).     const http = require ( 'http' );     // url module provides utilities for URL resolution and parsing.     // We are using variable as nodeUrl because we have already     // defined url variable below     const nodeUrl = require ( 'ur