DEV Community: Dev Learner

CRUD Operation

Dev Learner — Wed, 29 Dec 2021 19:50:54 +0000

CRUD Operation:
CRUD stands for Create, Read, Update and Delete. CRUD operation is a widely used operation in the database.
The importance of a database for dynamically representing a website is immense. And all the information sent to this database is again taken from this database to show any information on the website with the help of this CRUD operation.

Currently two types of database systems are used. A relational database such as SQL, SQL Server. On the other hand, non-relational database systems such as MongoDB.
Databases are created using a variety of backend applications. The codes for such a well-known backend application node JS.

Create Operation: Databases are created in the database using the Create operation. Inside it, information can be sent in the form of various collections. All collections of such orders are in one place. All product collections in one place etc.

Read Operation: Any data is read easily through read operation.

Update Operation: Any Data is update easily throw update operation.you can update your data of your database,you will use update operation.

Delete Operation:
You can delete any data from Database,you will use delete operation.
Only press delete button,you can delete data from Database.

Hooks

Dev Learner — Tue, 28 Dec 2021 19:35:58 +0000

React's new feature is the React hook.It has made many difficult things easier since it came. The hook can be compared to a hook. The hook helps to hold something in place, just as the hook holds something in place.We can store any data in external file in the form of stat with the help of hook. We can use this data by calling Hook as we need. This increases the mobility of the web.Hook is a method that does not require any kind of function. It can only be used in React. It cannot be used in ordinary JavaScript.To use the hook you have to call it at the beginning of the reaction.
The hook does not work inside a function or inside a loop or anywhere else.
So everyone has to call the start hook.

Pre-requisites for React Hooks
Node version 6 or above
NPM version 5.2 or above
Create-react-app tool for running the React App.

Custom Hooks
A custom Hook is a JavaScript function. The name of custom Hook starts with "use" which can call other Hooks. A custom Hook is just like a regular function, and the word "use" in the beginning tells that this function follows the rules of Hooks. Building custom Hooks allows you to extract component logic into reusable functions.

JavaScript DOM and Reduce

Dev Learner — Mon, 27 Dec 2021 19:59:27 +0000

DOM:
DOM is a great programming interface for XML or HTML documents. It represents a webpage in such a way that it can be easily modified into a programming language.
When we write HTML to a web page, we can see it with the browser.Again, if you want, you can see the HTML code directly from the resource.Basically what we see in the browser is a pity to see both but from here the document represents in an object-oriented way so that we can help is done with the language of a program.We can easily make an html5 dynamic in JavaScript.
Some change are:
Creating a new element Removing an existing.
Element Modifying an existing element.
Modifying a view Adding Removed.
Adding spelling Adding Removed.
Modifying Create.

Life has many uses for JavaScript manipulation.But we can easily do the manipulation through JavaScript so that the website does not take more people. This will make the website load faster and cost more MB.The address of a website can be presented in a very interactive way through Don Money Population. How to show a site and how beautiful it will be. Everything is determined by thoperation

Reduce:
Reduce is like filters, that's not the point. We talk to the earlist of the program about the function of the ear. It's easy to hold on to the end of a particular reading at a certain time. May be perfect for operation

Example:
var array=[2,3,54,23] var totalNum=array.reduce((sum){ return sum; }, 0);

Reault:

Total:82

Hoisting,Scope in JavaScript

Dev Learner — Sun, 26 Dec 2021 18:41:29 +0000

Hoisting:
Hoisting is a default behavior of JavaScript. JavaScript always takes all its declarations first. It can be said that this is one of its habitual actions.And this behaviour is called hoisting.
Since it is hosted, we can call before declaring any function.
I am trying to explain the matter through the following example.

Here is Input:

numberSum(); function numberSum(){ var a=32; var b=43; var sum=a+b; console.log(sum) }

Here is Output:

75

Scope:

Scooping is one of the most important aspects of JavaScript. A declared function can be used in some places and not in other places. It can be accessed from any place. .
There are two two kinds of scoping.
1.Local Scope,
2.Global Scope,
Local Scope: Usually the variables declared inside the function are the local variables of that function.
The scope of such variables is local.This means that this variable can only be accessed inside the declared function. It cannot be used for any other function.
Global Scope: If a variable is not declared inside a function, then it is a global scope. This means that a variable declared anywhere outside the function is a global scope. Global variable can be accessed from inside any function or from any place.

CSS Visibility Concept

Dev Learner — Thu, 23 Dec 2021 09:20:37 +0000

CSS Visibility is an important concept. It can easily express the visibility of an element.
Today I will try to give you an idea about this important concept of CSS.
CSS Visibility is a CSS property that indicates whether an element will remain visible or invisible in the user interface.There are many kinds of visibility value.
These are visible,hidden,initial,collapse,inherit etc.
Visible Definition: It is the default value. It is means any element are visible,you can provide it.It gives specific hight and width. If you can change hight and width, you will do it.
Hidden Definition: It inticates that the element is invisible but stay same hight and width.
Initial Definition : It is set property from it’s default value.
Inherit Definition: It set property from its parents value.
Collapse Definition: It is used only for table element. It removes column or row.That means you can invisible column or row,you can use collapse value.

Example Of CSS Visibility:

<!DOCTYPE html>

       This is CSS Visibility Item

    </title> 

    <style> 

        h3 { 

            color:Goldenrod
        }

.visibility{
visibility :visible;
}
.visibility-hidden{
visibility:hidden;
}

</head> 

<body> 

    <h1>Welcome Naim's blogs page</h3>

Time and wait for none <\p>

</body>