Non-standard
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

Logs the number of times that this particular call to count() has been called. This function takes an optional argument label.

Note: This feature is available in Web Workers.

If label is supplied, this function logs the number of times count() has been called with that particular label.

If label is omitted, the function logs the number of times count() has been called at this particular line.

For example, given code like this:

function greet() {
  console.count();
  return "hi " + user;
}

var user = "bob";
greet();
user = "alice";
greet();
greet();
console.count();

Console output will look something like this:

"<no label>: 1"
"<no label>: 2"
"<no label>: 3"
"<no label>: 1"

Note the final line of log output: the separate call to count() at line 11 is treated as an independent event.

If we pass the user variable as the label argument to the first invocation of count(), and the string "alice" to the second:

function greet() {
  console.count(user);
  return "hi " + user;
}

var user = "bob";
greet();
user = "alice";
greet();
greet();
console.count("alice");

We will see output like this:

"bob: 1"
"alice: 1"
"alice: 2"
"alice: 3"

We're now maintaining separate counts based only on the value of label. Because the label "alice" in line 11 matched the value of user twice, it is not considered an independent event.

Syntax

console.count([label]);

Parameters

label
A string. If this is supplied, count() outputs the number of times it has been called at this line and with that label.

Specifications

Specification Status Comment
Console API
The definition of 'console.count()' in that specification.
Editor's Draft Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) 30.0 (30.0) (Yes) (Yes) (Yes)
Available in workers (Yes) 38.0 (38.0) (Yes) (Yes) (Yes)
Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support ? 30.0 (30.0) ? ? ?
Available in workers ? 38.0 (38.0) ? ? ?

Document Tags and Contributors

 Contributors to this page: Sebastianz, chrisdavidmills, cvrebert, teoli, Korikulum, jaydeepw, wbamberg
 Last updated by: Sebastianz,