Where does a program start at?
This is live notes from a talk about how programs are executed
Different programming projects have programs that start execution in different places. Let us look at some common examples.
- Javascript - starts from the top of the file. The file to run is usually specified in
package.json. - Python - starts from the top of the file. The file to run is mostly specified from command line. (Eg:
python setup.py) - R - starts from the top of the file. In R studio, we can run any line we want. (Python notebooks are similar)
- Java - “main” method of whichever class we specify. Depends.
- Modern web projects - index.html, script tags within html, package.json, build scripts
- Android - AndroidManifest.xml, lifecycle methods.
The biggest difference is between Object-Oriented languages like Java and scripting languages like javascript and python. They run programs in completely different ways.