Page 220 - Web Applications (803) Class 12
P. 220
Helpful Links: For teachers, students, and parents, the Web offers a wealth of good tools. It is quite
beneficial to provide links to some of these sources. Make sure to periodically check the links to see if the
resources are still accessible. Learning communities and lesson plan ideas are accessible to teachers with
ease. Links to reference, “ask an expert,” and virtual museum websites are available to students. Links that
parents may find interesting can also be added.
Recap Zone
Ð JavaScript is essentially an interpreted programming language.
Ð It was initially built into web browsers so that client-side scripts could communicate dynamically,
control the browser, interact with the user, and modify the contents of documents.
Ð Along with a basic collection of language components like operators, control structures, and statements,
core JavaScript also includes a core set of objects including Array, Date, and Math.
Ð JavaScript is typically embedded into an HTML document using the <script> tag.
Ð JavaScript scripts are categorized as inline, internal and external script.
Ð A JavaScript variable (also known as an identifier) is a storage location in the memory.
Ð The conditional operator in JavaScript assigns a value to a variable based on some condition.
Ð typeof is a type checking operator in JavaScript that returns the datatype of the operand passed to it.
Ð JavaScript has several datatypes like String, Boolean, Number etc.
Ð JavaScript uses double-precision 64-bit numbers whereas strings are collections of characters.
Ð When a variable is declared but not given a value, its type is undefined by default.
Ð If and else support conditional statements in JavaScript.
Ð The switch statement is used to pick one of many code blocks to be performed.
Ð JavaScript offers various loops – for, while and do…while.
Ð When a user enters inaccurate information, the developer will utilise an alert box to show the user a
warning or error.
Ð prompt( ) method asks the user to enter a value. It has two buttons, one for ‘Ok’ and one for ‘Cancel’.
Ð The confirm( ) method is used to obtain confirmation from the user about an action.
Ð The String object offers formatting and string manipulation methods and properties.
Ð Numerous mathematical operations are supported by the Math object.
Ð Objects represent entities from the outside world that we want to express in our programs through
properties, and methods.
Ð An array is a special variable, with the capacity to hold several values.
Ð A block of code created specifically to carry out a specific task is referred to as a JavaScript function.
Ð An event is defined as a change in an object's state.
Ð The act of responding to events is known as event handling.
Ð JavaScript uses event handlers to handle HTML events.
218 Touchpad Web Applications-XII

