Should I copy-paste someone else's code?

Question

Programming

I'm a beginner web programmer and I'm interested in this question.
1. Should I borrow someone else's code if it solves my problem?
2. Question for experienced programmers. Do you use copypasta? What percentage does it take in your projects?
3. Does it make sense to create text files, or upload code to GitHub for the same type of tasks?

The purpose of this is to speed up development.

Thanks for answers! All the best!

Answer 1

1. If your goal is to complete the task - yes, if you learn - no.
2. ~10% maximum, there are frameworks instead of copy-pastes)
3. I didn’t quite understand, but it’s worth learning to work with git anyway

Answer 2

You don't understand OOP. More precisely, one of its main principles is code reuse.
If you're an engineer, your job is to take the building blocks and glue them together with a little bit of your code.
The ranking of your qualification occurs at the moment when you are able to choose from N technologies and show that it will be more profitable or write a bicycle for the same purpose.

Answer 3

From the point of view of the law, someone else's code is an author's work. Its use is possible on the terms of the author. If you use for educational purposes - consent is not required. But they should always indicate (in the comments or About) the author. Use for commercial purposes (without consent) may be punishable.
In general: a must use. But do not stupidly copy and paste, but understand and see how it works.

Answer 4

1. Worth it if you understand it.
2. 0-10%
3. Always use git