JavaScript Academy · Lesson

Beyond console.log

Use table, group, warn, error, and assert.

Beyond console.log is a free JavaScript Academy lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the JavaScript Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.

More Than Log

The console object offers many methods beyond console.log. Each communicates a different intent and can render output in useful ways.

console.log("plain message")
console.info("informational")

console.warn

console.warn emits a warning. In a browser it appears with a yellow highlight, signaling a non-fatal issue worth attention.

console.warn("This API is deprecated")

console.error

console.error reports an error. It is styled distinctly and, in browsers, includes a stack trace to help locate the problem.

console.error("Failed to load data")

console.info and debug

console.info and console.debug behave like log but convey severity. Tools can filter messages by these levels.

console.info("Server started")
console.debug("Cache size is 42")

console.table

console.table renders arrays and objects as a formatted table, making structured data far easier to scan than a plain log.

const users = [
  { name: "Ann", age: 30 },
  { name: "Bob", age: 25 }
]
console.table(users)

console.group

console.group starts an indented, collapsible section. Messages logged after it are nested until you call console.groupEnd.

console.group("User details")
console.log("Name: Ann")
console.log("Age: 30")
console.groupEnd()

Nested Groups

Groups can nest inside each other to mirror a hierarchy, with each level adding more indentation.

console.group("Order")
console.log("id: 1")
console.group("Items")
console.log("Book")
console.groupEnd()
console.groupEnd()

console.assert

console.assert logs an error only when its first argument is falsy. It is a quick way to flag broken assumptions without halting execution.

const total = 10
console.assert(total > 0, "total should be positive")
console.assert(total > 100, "total is unexpectedly small")

console.count

console.count tracks how many times a labeled line has run, which is handy for spotting unexpected repeated calls.

function ping() {
  console.count("ping")
}
ping()
ping()
ping()

console.time

console.time and console.timeEnd measure how long a block of code takes, printing the elapsed duration with a matching label.

console.time("loop")
let sum = 0
for (let i = 0; i < 1000; i++) { sum += i }
console.timeEnd("loop")

Choosing the Right Method

Use warn and error for problems, table for structured data, group to organize related logs, and assert to validate assumptions. Clear logging speeds up debugging.

console.warn("low memory")
console.table([{ id: 1 }, { id: 2 }])

Quick Check

Test your console method knowledge.

Recap

Recap: The console has rich methods beyond log.

warn and error signal severity
table renders structured data
group organizes nested logs
assert flags failed conditions

console.table([{ a: 1 }, { a: 2 }])
console.warn("done")

Frequently asked questions

Is the “Beyond console.log” lesson free?

Yes — the full text of “Beyond console.log” is free to read here on the web, and the JavaScript Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the JavaScript Academy course, upgrade to CoddyKit PRO.

What will I learn in “Beyond console.log”?

Use table, group, warn, error, and assert. You practise JavaScript Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start JavaScript Academy?

No prior experience is required. JavaScript Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.

How long does the “Beyond console.log” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this JavaScript Academy lesson?

Yes. Every JavaScript Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

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