JavaScript_Introduction_Presentation.pptx

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1. Introduction to JavaScript JavaScript is a versatile language primarily used for web development. It interacts with HTML and CSS to create dynamic web pages. JavaScript is used for manipulating the DOM, handling events, and more. <script> console.log("Hello, JavaScript!"); </script>

2. JavaScript DOM (Document Object Model) DOM is a programming interface for HTML and XML documents. It represents the structure of a document as a tree of objects. JavaScript can be used to manipulate the DOM to create interactive web pages. document.getElementById("demo").innerHTML = "Hello DOM!";

3. Exception Handling in JavaScript Exception handling ensures that errors are caught and managed properly. JavaScript provides the try...catch...finally structure for handling exceptions. try { let x = 10; let y = x + z; // z is undefined } catch (error) { console.log("Error: " + error.message); }

4. JavaScript Validation JavaScript validation ensures that user input meets the required format before submission. It is commonly used in forms to validate data. function validateForm() { let email = document.getElementById("email").value; if (email === "") { alert("Email is required."); return false; } }

5. JavaScript Built-in Objects JavaScript has several built-in objects such as Array, String, Date, and Math. These objects provide methods and properties for common tasks. let arr = [1, 2, 3]; console.log(arr.length); // Outputs: 3

6. JavaScript Event Handling Event handling allows JavaScript to react to user actions such as clicks or keypresses. It is achieved through event listeners or event handlers. document.getElementById("btn").addEventListener("click", function() { alert("Button clicked!"); });

7. JSON in JavaScript JSON stands for JavaScript Object Notation and is a lightweight format for data exchange. It is easy for both humans and machines to read and write. let person = { "name": "John", "age": 30, "city": "New York" }; let jsonString = JSON.stringify(person); console.log(jsonString);