nodejs/doc/api/stdio.markdown

console

Browser-like object for printing to stdout and stderr.

console.log()

Prints to stdout with newline. This function can take multiple arguments in a printf()-like way. Example:

console.log('count: %d', count);

If formating elements are not found in the first string then util.inspect is used on each argument. See util.format() for more infomation.

console.info()

Same as console.log.

console.warn()

console.error()

Same as console.log but prints to stderr.

console.dir(obj)

Uses util.inspect on obj and prints resulting string to stderr.

console.time(label)

Mark a time.

console.timeEnd(label)

Finish timer, record output. Example

console.time('100-elements');
for (var i = 0; i < 100; i++) {
  ;
}
console.timeEnd('100-elements');

console.trace()

Print a stack trace to stderr of the current position.

console.assert()

Same as assert.ok().