Node.js v0.9.9 Manual & Documentation


Stability: 4 - API Frozen
  • Object

For printing to stdout and stderr. Similar to the console object functions provided by most web browsers, here the output is sent to stdout or stderr.

console.log([data], [...])#

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

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

If formatting elements are not found in the first string then util.inspect is used on each argument. See util.format() for more information.[data], [...])#

Same as console.log.

console.error([data], [...])#

Same as console.log but prints to stderr.

console.warn([data], [...])#

Same as console.error.


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


Mark a time.


Finish timer, record output. Example:

for (var i = 0; i < 100; i++) {


Print a stack trace to stderr of the current position.

console.assert(expression, [message])#

Same as assert.ok() where if the expression evaluates as false throw an AssertionError with message.