Speaking JavaScript (2014)

Part IV. Tips, Tools, and Libraries

Chapter 27. Language Mechanisms for Debugging

The following three language constructs help with debugging. They should obviously be complemented by a proper debugger:

§ The debugger statement behaves like a breakpoint and launches the debugger.

§ console.log(x) logs the value x to the console of the JavaScript engine.

§ console.trace() prints a stack trace to the engine’s console.

The console API provides more debugging help and is documented in more detail in The Console API. Exception handling is explained in Chapter 14.