JAVASCRIPT Programming What is JavaScript? • It is a programming language that is used to make web pages interactive • It is object based • It is executed on the client’s or user’s computer • It is an interpreted language JavaScript is NOT Java! • Though they have similar names, JavaScript and Java are not the same • Java is a complex programming language compared to Java • Java is in the same category as C/C++, VB, Python etc. • JavaScript is a scripting language Programming fundamentals Variables Conditionals Comparisons & Operators Events Objects Functions Program Flow Data Types Prototypes Arrays What you need to run JavaScript • JavaScript is executed on a user’s browser such as • Google chrome • Mozilla Firefox • Internet Explorer • Safari • Opera JavaScript vs HTML JavaScript and HTML are completely different languages HTML is a markup language whereas JavaScript is a programming language JavaScript is written inside HTML JavaScript uses events and actions to make webpages interactive What can you do with JavaScript? Create cookies, build apps with JavaScript framework 1 Detect browser being used on a device 2 Validate forms e.g passwords, format checks 3 Create animations, slideshows, scrollers, JavaScript Coding • JavaScript is embedded in the HTML code, between the open and close HTML tags • <HTML> • <Body> • <SCRIPT> • alert(“Hello Guys!”) • </SCRIPT> • </Body> • </HTML> OUTPUTTING DATA • There are two ways you can output data to an HTML document. This can be done using: • document.write() • .innerHTML document.write() This function is used to output values passed to it. For example, document.write(“Hello World”) will print the text Hello World when run in the browser You should notice how the text appears on the webpage. We have no control of where the text should appear .innerHTML • When you want to print to a specific point on the webpage, you can use the .innerHTML • This is done by naming elements within the HTML code • For example: <p ID=“parag1”></p> • In the script tags, you can instruct JavaScript to add text to the document at that position using the ID tag • <Script> • Document.getElementyID(“parag1”).innerHTML = “Hello World” • </script> Pop-up boxes •These can be used to display text or other information •The text or information is not written on the webpage like when you use document.write and .innerHTML. •Instead, the text is displayed as an overlay, on top of the webpage