01 · Hello, Apex: your first class

Open the Developer Console, write ten lines, run them anonymously — and understand every one of them.

Where Apex runs

Apex executes on Salesforce's servers, inside a transaction, under limits. That one sentence explains most of what makes it different from JavaScript or Python.

Execute Anonymous is your REPL

The Developer Console's Execute Anonymous window runs any block instantly. It is how you will test every idea in this course before committing it to a class.

Practice in your org

• Open your Developer Edition org and follow along step by step
• Change one thing at a time and note what happens
• When something breaks, read the error before searching for it