console: warn() static method

The console.warn() static method outputs a warning message to the console.

Note: This feature is available in Web Workers

Note: In Chrome and Firefox, warnings have a small exclamation point icon next to them in the console log.

Syntax

warn(obj1)
warn(obj1, /* …, */ objN)
warn(msg)
warn(msg, subst1, /* …, */ substN)

obj1 … objN: A list of JavaScript objects to output. The string representations of each of these objects are appended together in the order listed and output to the console.
msg: A JavaScript string containing zero or more substitution strings, which are replaced with subst1 through substN in consecutive order.
subst1 … substN: JavaScript objects with which to replace substitution strings within msg. This gives you additional control over the format of the output. See Using string substitutions for a description of how substitutions work.