console

Baseline Widely available

This feature is well established and works across many devices and browser versions. Its been available across browsers since 2015 7.

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See full compatibility

console (Firefox ) . , .

console . Window, WorkerGlobalScope . Window.console console .

console.log("   ");

: Web Worker .

console.assert(): false .
console.clear(): .
console.count(): .
console.countReset(): .
console.debug(): debug .
console.dir(): JavaScript . .
console.dirxml(): XML/HTML , JavaScript .
console.error(): . .
console.exception(): error() .
console.group(): , . groupEnd() .
console.groupCollapsed(): , . group() , groupCollapsed() . groupEnd() .
console.groupEnd(): .
console.info(): . .
console.log(): . .
console.profile(): (Firefox ) . .
console.profileEnd(): . (Firefox ) .
console.table(): .
console.time(): . 10,000 .
console.timeEnd(): , .
console.timeStamp(): .
console.trace(): .
console.warn(): . .

. , console.log(), console.info(), console.warn(), console.error() . , .

. , . , .

var someObject = { str: "Some text", id: 5 };
console.log(someObject);

bash

[09:27:13.475] ({str:"Some text", id:5})

var car = "Dodge Charger";
var someObject = { str: "Some text", id: 5 };
console.info("My first car was a", car, ". The object is: ", someObject);

bash

[09:28:22.711] My first car was a Dodge Charger. The object is: ({str:"Some text", id:5})

log() .

%o %O: JavaScript . .
%d %i: . . console.log("Foo %.2d", "1.1") 0 Foo 01 .
%s: .
%f: . . console.log("Foo %.2f", "1.1") Foo 1.10 .

: Chrome

. ...

for (var i = 0; i < 5; i++) {
  console.log("Hello, %s. You've called me %d times.", "Bob", i + 1);
}

bash

[13:14:13.481] Hello, Bob. You've called me 1 times.
[13:14:13.483] Hello, Bob. You've called me 2 times.
[13:14:13.485] Hello, Bob. You've called me 3 times.
[13:14:13.487] Hello, Bob. You've called me 4 times.
[13:14:13.488] Hello, Bob. You've called me 5 times.

"%c" CSS .

console.log(
  "This is %cMy stylish message",
  "color: yellow; font-style: italic; background-color: blue;padding: 2px",
);

, CSS .

[]

"%c" .

console.log(
  "Multiple styles: %cred %corange",
  "color: red",
  "color: orange",
  "Additional unformatted message",
);

%c CSS . (Firefox , )

: . padding, margin display: inline-block .

. console.group() . console.groupCollapsed() , .

console.groupEnd() . ...

console.log("This is the outer level");
console.group("First group");
console.log("In the first group");
console.group("Second group");
console.log("In the second group");
console.warn("Still in the second group");
console.groupEnd();
console.log("Back to the first group");
console.groupEnd();
console.debug("Back to the outer level");

[Demo of nested groups in Firefox console]

. console.time() . . , console.timeEnd() . , .

...

console.time("answer time");
alert("Click to continue");
console.timeLog("answer time");
alert("Do a bunch of other stuff...");
console.timeEnd("answer time");

, , .

[]

: , . , .

. console.trace() . ...

function foo() {
  function bar() {
    console.trace();
  }
  bar();
}

foo();

[]

Specification
Console # console-namespace

Firefox console Firefox .

Firefox
: Firefox API
:

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