node. JS V0.10.31API Manual-Console

Control Desk

• Object

Used to print characters to stdout and stderr. Similar to the console object functions provided by most WEB browsers, here is the output to stdout or stderr.

When the output target is a terminal or a file, the console function is synchronized (to prevent the loss of information in case of premature exit). They are asynchronous when the output target is a pipe (prevents blocking for too long).

In other words, in the following example, stdout is non-blocking, while stderr is blocked.

$ node Script JS 2  >  error  Log |  tee info Log  

in daily use, you don't need to worry too much about blocking/non-blocking differences unless you need to log large amounts of data.

Console.log ([data], [...])Print to stdout and start a new line. This function can be like printf()that takes multiple parameters, such as:

console  log   (  " Count:%d '   count"   

If a formatting element is not found in the first string, then util.inspect will be applied to each parameter. See Util.format ().

Console.info ([data], [...])with console.log.

Console.error ([data], [...])with console.log, but output to stderr.

Console.warn ([data], [...])with console.error.

Console.dir (obj)the objUse util.inspectand output the resulting string to stdout. This function ignores objany customizations on the inspect().

Console.time (label) marks the time.

Console.timeend (label)End timer, record output. Example:

Console. Time(' 100-elements '); for (varI= 0;I<  -;I++) {  ;}Console.Timeend(' 100-elements ');

Console.trace (message, [...])output stderr through formatted messages and stack traces to the current location ‘Trace :‘.

Console.assert (value, [message], [...])with theAssert.ok ()same, but error messages use  util.format(message...)to format.

node. JS V0.10.31API Manual-Console