How to know which Programming language you need to use?

Answer 1

Go to Wikipedia,look for the programming language you're thinking about and read the Wikipedia page. You'll get the specific use of those languages.

Based on my knowledge...

Java/Kotlin for Android.
Objective-c/Swift for iOS/macOS
JavaScript for Website (HTML is markup[structure] and css is styling [look],while JavaScript is the script [the magic])..
C/C++ for system programming,as well as for anything (yeah,just anything [but require really long time to learn])..
C# and other .NET language for Windows.
Dart( and Flutter Framework) for Fushcia (Google's upcoming OS).
Python for programming things faster ( deep learning/machine learning) than it would take in any other programming language.
Lua for game programming (It's one of the favourite for game developers).
mySQL for database (got some others too).
PHP for server-side.
There are lots of other alternative for server...This includes:
JavaScript (Node.js), Ruby ( Ruby on Rails), Python (Django), Java(Spring), C#(ASP.NET), Erlang(Phoenix) and many more using Apache.
There are templating language too, such as mustache,elm and pug.
Processing (Java based Runtime),for graphics.
Assembly for accessing CPU.
Erlang/Elixir for large traffic servers.
That's all I remember now.

Answer 2

That depends on what you're trying to achieve.

⏺️For any kind of website related works:
1.HTML
2.CSS
3.Javascript

knowledge on the above three is required as basic.

✨For web development: Start with HTML, and then move on to CSS, JavaScript, Python,jQuery,, and SQL.

Or

HTML,CSS, jQuery,SQL,PHP

or

🐍Python3 and Django for building strong and very rich website ( flask is used for small website,but Django for everything)

kivy ( a Python Program for anroid )is used for making android apps.

✨For general application :
programming: Python, C++, and Ruby; then Java, C#, or Swift, based on the platform you're targeting.

➡️For details:
https://www.sololearn.com/FAQ

🔷Here is a very rich video, detailed (step by step) guidelines for starting online Career ( learning Web Development and other Programs):
⬇️⬇️⬇️
https://youtu.be/Zftx68K-1D4

🔼🔼Watch the above video attentively and then decide yourself.

⏩⏩A very good reference:
https://www.sololearn.com/Discuss/284542/?ref=app

⏬⏬By August Mein:⏬⏬
1. Choosing your first Language

You can choose any language.
if you can't decided here the guide :

HTML is used to make web structure.

CSS is used to give style or animate web

JAVASCRIPT is used to make dynamic web (you can even make game)

PHP is server side scripting language

SQL is database manajemen in server side

C++ is multiplatform OOP based programming language (you can make many app including Games)

C# is more spesific (windows os) than C++
Java is used to build app that can run on any devices (including Android). JAVA is not JAVASCRIPT

Python is multiplatform OOP based programming languages with easy syntax (compared to other OOP Language)
Swift is for building apple / IOS app .

https://www.sololearn.com/Discuss/437973/?ref=app

https://www.sololearn.com/discuss/1033194/?ref=app
https://www.sololearn.com/discuss/1062064/?ref=app