Suparnar Taina

Suparnar Taina

1600762224

How to Explain Javascript .filter() .map() and .reduce() to SQL users

I found using .filter() .map() and .reduce() Array methods could help to reduce code complexity and simplify many typical array data processing tasks.Looking at  http://kangax.github.io/compat-table/es5/#test-Array_methods, you can confirm these methods are compatible with almost any modern desktop/mobile browser.

A good approach to understand how to use **.filter() .map() **and .reduce() is to compare each one to SQL data operations in SELECT statements.

Consider the following SQL query:

SELECT
category, SUM(amount) as total
FROM transactions
WHERE status = 'active'
GROUP BY category

A common SQL command could have three type of data operations: map or select fields to display ( category, total ), filter data using conditions (status = ‘active’), and reduce the results generating summary data using an aggregate function (SUM) specifying some aggregate groups (category). In Javascript, these operations could be performed using .filter() .map() and .reduce()

#javascript #sql

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How to Explain Javascript .filter() .map() and .reduce() to SQL users
Cayla  Erdman

Cayla Erdman

1594369800

Introduction to Structured Query Language SQL pdf

SQL stands for Structured Query Language. SQL is a scripting language expected to store, control, and inquiry information put away in social databases. The main manifestation of SQL showed up in 1974, when a gathering in IBM built up the principal model of a social database. The primary business social database was discharged by Relational Software later turning out to be Oracle.

Models for SQL exist. In any case, the SQL that can be utilized on every last one of the major RDBMS today is in various flavors. This is because of two reasons:

1. The SQL order standard is genuinely intricate, and it isn’t handy to actualize the whole standard.

2. Every database seller needs an approach to separate its item from others.

Right now, contrasts are noted where fitting.

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Coy  Roberts

Coy Roberts

1600510680

Definitive Guide to Understand Javascript Array reduce()

Javascript array reduce() is an inbuilt method that is used to apply a function to each element in the array to reduce the array to a single value. The reduce() function executes the provided function for each value of an array from left-to-right. The return value of a function is stored in an accumulator.

Understanding Javascript array reduce()

JavaScript array reduce() is one of the pioneer function of functional programming. The reduce() method accepts two parameters, the total and the current value. If you want to add all the values of an array, then use the array reduce() function.

It is similar to both  Javascript map() and  Javascript filter() but, it differs in the callback arguments.

The callback now receives an accumulator (it accumulates all the return values. Its value is the accumulation of a previously returned accumulations), a current value, a current index, and finally, the whole array.

#javascript #javascript map #javascript filter #javascript array reduce

map(), filter() and reduce() in JavaScript.

**_map, filter and reduce _**are essentially just some of the most well-known, easy to use, higher-order functions that run provided callback on each element of an array.

In this article, we will explore how using map(), filter(), and reduce() can help make our code:

**1.**Easy to comprehend.

2. Less prone to side effects as these function don’t modify the actual array, and instead create a new one.

**3. **Avoid explicit loops.

Let’s explore and familiarize ourselves with these functions.

#functional-programming #filters #maps #javascript #reduce

Coy  Roberts

Coy Roberts

1600868220

Array Foreach, Map, Filter, Reduce, Concat Methods in Javascript

In this tutorial, we will see Javascript Array Foreach, Map, Filter, Reduce, Concat Methods. I dedicate this article only for these methods because, in Pure Functional Programming, this kind of method is required to perform some operations on an Array.

If you do not know What Pure Functions is, then check out my Pure Functions in Javascript article on this website.

Arrays

All the programming languages have this kind of Data Structure to hold and manipulate the data and Javascript is not different.

We all know Arrayscollection of variables, and we all have used to perform some operations like Creating an array, Removing an Item from an Array, Sorting the data of an Array and other manipulations.

In Functional Programming, we are using functions like foreach, map, filter, reduce, concatAll and other Higher Order Functions. So today I am describing these functions in deep and show you how you can use it in various scenarios.

#javascript #programming #foreach #map #filter #reduce

Ruth  Nabimanya

Ruth Nabimanya

1621850444

List of Available Database for Current User In SQL Server

Introduction

When working in the SQL Server, we may have to check some other databases other than the current one which we are working. In that scenario we may not be sure that does we have access to those Databases?. In this article we discuss the list of databases that are available for the current logged user in SQL Server

Get the list of database
Conclusion

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