Console.count()
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
.
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) | ? | ? | ? |
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/console/count