jQuery is a fast, small, and feature-rich JavaScript library. It makes things like HTML document traversal and manipulation, event handling, animation, and Ajax much simpler with an easy-to-use API that works across a multitude of browsers. With a combination of versatility and extensibility, jQuery has changed the way that millions of people write JavaScript.

DOM Traversal and Manipulation

Get the <button> element with the class 'continue' and change its HTML to 'Next Step...'

1	$( "button.continue" ).html( "Next Step..." )

Event Handling

Show the #banner-message element that is hidden with display:none in its CSS when any button in #button-container is clicked.

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var hiddenBox = $( "#banner-message" ); $( "#button-container button" ).on( "click", function( event ) { hiddenBox.show(); });

Ajax

Call a local script on the server /api/getWeather with the query parameter zipcode=97201 and replace the element #weather-temp's html with the returned text.

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$.ajax({ url: "/api/getWeather", data: { zipcode: 97201 }, success: function( result ) { $( "#weather-temp" ).html( "<strong>" + result + "</strong> degrees" ); } });