console: count() static method

label Optional

A string. If supplied, count() outputs the number of times it has been called with that label. If omitted, count() behaves as though it was called with the "default" label.

None (undefined).

For example, given code like this:

function greet(user) {
  console.count();
  return `hi ${user}`;
}

greet("bob");
greet("alice");
greet();
console.count();

Console output will look something like this:

"default: 1"
"default: 2"
"default: 3"
"default: 4"

The label is displayed as default because no explicit label was supplied.

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

function greet(user) {
  console.count(user);
  return `hi ${user}`;
}

greet("bob");
greet("alice");
greet("alice");
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.

• Microsoft Edge's documentation for console.count()
• Node.JS documentation for console.count()
• Google Chrome's documentation for console.count()