Call Stack

Summary

The data structure JavaScript uses to track function calls — each call is pushed on, and popped off when it returns; a 'stack overflow' happens when it grows too deep. The stack provides the execution order for synchronous JavaScript and is also one of the most useful tools for understanding recursion and debugging runtime failures.

• 1Write a recursive function without a base case and watch the stack overflow error. Validate your understanding by applying it in a small practical example.
• 2Open DevTools' 'Call Stack' panel while paused on a breakpoint. Inspect at least one real example and note what each important field or stage represents.
• 3Understand why JS is single-threaded — it has one call stack.