The console Object

The console object is your main tool for printing output and debugging. It has more methods than just log.

log, error, and warn

console.log("Normal message");
console.error("Something went wrong"); // goes to stderr
console.warn("Be careful");            // a warning

console.error and console.warn write to the error stream, which is useful for separating errors from normal output.

Printing variables

You can pass several values, and Node prints them separated by spaces:

const user = { name: "Fausto", age: 30 };
console.log("User:", user); // User: { name: 'Fausto', age: 30 }

console.table

For arrays and objects, console.table shows a neat grid:

const fruits = [
  { name: "apple", price: 2 },
  { name: "banana", price: 1 },
];

console.table(fruits);

Timing code

console.time("loop");
for (let i = 0; i < 1000000; i++) {}
console.timeEnd("loop"); // loop: 3.2ms

Summary

Use console.log for normal output, error and warn for problems, and table to display data clearly while debugging.