use the console.log method to send message to console in your javascript, for example:
console.log('Hello,my friend!')
What's more, you can use console.warn() for warn messaging, console.error() for error messaging, console.info() for infomation message, for example:
console.warn('console is offline')
console.error('connection failed')
console.info('hahaha')
Check the differences between these three by pressing Ctrl+shift+J (windows) or Cmd+opt+J(Mac) in chrome.
Using the %c format to style the console!
console.log('%cI am styled!', '
color: #86CC00;
background-color:yellow;
font-size: 20px;
padding: 3px;')
These are called Console API which helps you to write information to the console, create javascript profiles and start a debugging session, and there are more API to try with.
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