| # console |
| |
| Stability: 4 - API Frozen |
| |
| * {Object} |
| |
| <!--type=global--> |
| |
| 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. |
| |
| The console functions are synchronous when the destination is a terminal or |
| a file (to avoid lost messages in case of premature exit) and asynchronous |
| when it's a pipe (to avoid blocking for long periods of time). |
| |
| That is, in the following example, stdout is non-blocking while stderr |
| is blocking: |
| |
| $ node script.js 2> error.log | tee info.log |
| |
| In daily use, the blocking/non-blocking dichotomy is not something you |
| should worry about unless you log huge amounts of data. |
| |
| |
| ## 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. |
| |
| ## console.info([data], [...]) |
| |
| Same as `console.log`. |
| |
| ## console.error([data], [...]) |
| |
| Same as `console.log` but prints to stderr. |
| |
| ## console.warn([data], [...]) |
| |
| Same as `console.error`. |
| |
| ## console.dir(obj) |
| |
| Uses `util.inspect` on `obj` and prints resulting string to stdout. |
| |
| ## 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(label) |
| |
| 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`. |
| |
| [assert.ok()]: assert.html#assert_assert_value_message_assert_ok_value_message |
| [util.format()]: util.html#util_util_format_format |