Interactive Usage
Notes for Java programmers:
The Wolfram Language is interpreted, meaning any piece of code can be run immediately. Java code must be compiled before execution, making truly interactive programming impossible.
Notes for Python programmers:
You can use the Wolfram Language interactively, like a much-enhanced version of the Python interactive shell, that supports immediate code assistance, graphics, inline interfaces, etc.
In a Wolfram Notebook on the desktop or web, just type an input, then press SHIFT+ENTER to compute:
In[n] and Out[n] label successive inputs and outputs. You can refer to the most recent output as %—though it's usually better to define a variable.
Notes for Python programmers:
% in the Wolfram Language serves a similar role to _ in the Python interactive shell.