You can write messages to the system console for debugging purposes.

The Console API is mandatory for Tizen mobile, wearable, and TV profiles, which means that it is supported on all mobile, wearable, and TV devices. All mandatory APIs are supported on the Tizen Emulators.

The main features of the Console API include:

• Writing log messages and errors

  You can write simple log and error messages to the system console.

• Formatting objects

  You can print a JavaScript representation of a specified object.

• Timing

  You can measure the time elapsed during an operation.

The global console object contains some additional features defined by Cordova.

Prerequisites

To perform any Cordova-related operations, you must wait until Cordova is fully set up (the deviceready event occurs):

document.addEventListener('deviceready', onDeviceReady, false);

function onDeviceReady() {
    console.log('Cordova features now available');
    console.log('Connection type: ' + navigator.connection.type);
}

The console global object is available earlier, but it points to a default system console.

Writing Log Messages and Errors

To write simple log and error messages to the system console, use the log() and error() methods:

console.log('console.log works well');
console.error('console.error works well');

Formatting Objects

To print a JavaScript representation of a specified object:

• To print without formatting:

  var john = {name: 'John', surname: 'Doe'};
  console.dir(john.name);
  

• To print with formatting, use %o:

  var john = {name: 'John', surname: 'Doe'};
  console.dir('my object %o', john);
  

Measuring Timing

To measure the time elapsed during an operation:

1. Start the timer and give it a label (a string), which is used to identify the timer:

   console.time('Big array initialization');
   

2. Perform some operation:

   var array = new Array(1000000);
   for (var i = array.length - 1; i >= 0; i -= 1) {
       array[i] = new Object();
   }
   

3. Stop the timer by passing the same label to the timeEnd() method:

   console.timeEnd('Big array initialization');
   

   The following output is shown in the system console:

   Big array initialization: 176ms