Web-Development-Applications Exam Dumps - WGU Web Development Applications (KVO1)

AJAX (Asynchronous JavaScript and XML) is used to request and update data in the background without reloading the web page.

AJAX Overview:

Purpose: Allows web pages to be updated asynchronously by exchanging data with a web server behind the scenes.

Benefits: Provides a smoother user experience by avoiding full page reloads.

Example:

Using XMLHttpRequest:

var xhr = new XMLHttpRequest();

xhr.open("GET", "data.json", true);

xhr.onreadystatechange = function() {

if (xhr.readyState === 4 && xhr.status === 200) {

var data = JSON.parse(xhr.responseText);

console.log(data);

}

};

xhr.send();

References:

MDN Web Docs - AJAX

W3Schools - AJAX Introduction

To call the sayHello method in the given JavaScript object, you need to use the object's name followed by the method name with parentheses.

Correct Method Call:

Given the object definition:

var obj = {

sayHello: function() {

alert("Hello");

}

};

To call the method sayHello on the object obj:

obj.sayHello();

Explanation:

Option A: Obj.sayHello; is incorrect syntax. The correct syntax is obj.sayHello();.

Option B: Window.sayHello(); is incorrect because the method is defined in the obj object, not the window object.

References:

MDN Web Docs - Functions

W3Schools - JavaScript Objects

The pattern attribute in the <input> element is used to specify a regular expression that the input's value must match for it to be considered valid. The given pattern -?\d{1,3}\.\d+ matches strings that represent decimal numbers with an optional negative sign, typically used for latitude and longitude values.

Pattern Explanation:

-? allows for an optional negative sign.

\d{1,3} matches one to three digits.

\. matches a literal dot.

\d+ matches one or more digits.

Usage Example:

<input type="text" pattern="-?\d{1,3}\.\d+" placeholder="Enter latitude or longitude">

This pattern ensures the input matches the format of latitude/longitude values.

References:

MDN Web Docs on <input> pattern attribute

Regular Expressions Documentation

Given the CSS selector a, ul, it targets all anchor () elements and all unordered list (

) elements independently. This means the CSS rule will be applied to each <a> and
element in the HTML document.

CSS Selector Analysis:

a: This part of the selector targets all <a> elements in the document.

,: The comma is a selector separator, meaning that each part of the selector list is applied independently.

ul: This part of the selector targets all

elements in the document.

Example:

Given HTML:

<a href="<a href="http://example.com/link0">http://example.com/link0 ">Link 0</a>

http://example.com/link1 ">Link 1</a>

• Hello

http://example.com/link2 ">Link 2</a>

https://example.com/link3 ">Link 3</a>

Sample

Given CSS:

a, ul {

color: red;

}

Affected Elements: All <a> and

elements will have the color set to red.

References:

MDN Web Docs - Comma combinator

W3C CSS Selectors Level 3