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| Section | Weight | Objectives |
|---|---|---|
| Topic 1: Variables, Types, and Collections | 23% | - Type coercion and type conversion - String manipulation and Date objects - Array manipulation (map, filter, reduce, forEach, find) - Variable declaration (var, let, const, scoping, hoisting) - JSON parsing and stringification |
| Topic 2: Testing | 7% | - Unit testing with Jest - Automated testing strategies - Test-driven development principles |
| Topic 3: Server Side JavaScript | 8% | - Node.js applications - Salesforce API integration - Modules and file operations |
| Topic 4: Debugging and Error Handling | 7% | - Logging strategies and debugging techniques - try-catch blocks |
| Topic 5: Objects, Functions, and Classes | 25% | - Higher-order functions and closures - Object creation, properties, and prototypal inheritance - ES6 Classes, constructors, methods, and inheritance - JavaScript modules (export, import) - Function declarations, expressions, and arrow functions |
| Topic 6: Browser and Events | 17% | - Browser Developer Tools - Event handling, propagation, bubbling, and capturing - DOM manipulation |
| Topic 7: Asynchronous Programming | 13% | - Event loop and asynchronous code execution - Callback patterns - Promises and async/await |
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NEW QUESTION # 67
Refer to the code:
01 console.log('Start');
02 Promise.resolve('Success').then(function(value) {
03 console.log('Success');
04 });
05 console.log('End');
What is the output after the code executes successfully?
Answer: A
Explanation:
________________________________________
Comprehensive and Detailed Explanation From Exact Extract JavaScript Knowledge console.log('Start') runs immediately (synchronous).
Promise.resolve().then(...) places the callback in the microtask queue. The .then handler does not run immediately.
console.log('End') runs next (still synchronous).
After the synchronous script finishes, the microtask queue runs, logging "Success".
Execution order:
Start
End
Success
This matches option B.
________________________________________
JavaScript Knowledge Reference (text-only)
Promise .then() callbacks execute after the current call stack finishes (microtask queue).
Synchronous logs run immediately, before promise callbacks.
NEW QUESTION # 68
Refer to the following code:
01 function Tiger(){
02this.Type = 'Cat';
03 this.size = 'large';
04 }
05
06 let tony = new Tiger();
07 tony.roar = () =>{
08 console.log('They\'re great1');
09 };
10
11 function Lion(){
12 this.type = 'Cat';
13 this.size = 'large';
14 }
15
16 let leo = new Lion();
17 //Insertcode here
18 leo.roar();
Which two statements could be inserted at line 17 to enable the function call on line 18?
Choose 2 answers.
Answer: A,B
NEW QUESTION # 69
A developer is setting up a Node,js server and is creating a script at the root of the source code, index,js, that will start the server when executed. The developer declares a variable that needsthe folder location that the code executes from.
Which global variable can be used in the script?
Answer: D
NEW QUESTION # 70
Refer to the HTML below:
<div id="main">
<ul>
<li>Leo</li>
<li>Tony</li>
<li>Tiger</li>
</ul>
</div>
Which JavaScript statement results in changing "Leo" to "The Lion"?
Answer: A
Explanation:
Comprehensive and Detailed Explanation From Exact Extract JavaScript Knowledge:
We want to select the first <li> under #main and change its content.
document.querySelector(selector) returns the first element matching the CSS selector.
In the DOM, the <li> elements under <ul> are children in order:
1st child: "Leo"
2nd child: "Tony"
3rd child: "Tiger"
li:nth-child(1) is the CSS pseudo-class that selects the first <li> inside its parent.
So:
document.querySelector('#main li:nth-child(1)').innerHTML = 'The Lion'; selects the first <li> ("Leo") inside #main and sets its innerHTML to "The Lion".
Why others are incorrect:
A . #main #Leo
There is no element with id "Leo". id is not set on the <li>, so the selector matches nothing.
B . li:second-child
There is no :second-child pseudo-class. The valid pseudo-class is :nth-child(2); and that would select "Tony", not "Leo".
C . '#main li,Leo'
This selector means "all #main li and all elements named <Leo>".
There is no <Leo> tag, and querySelectorAll returns a NodeList, which does not have a single innerHTML property.
Therefore, D is the correct statement.
Study Guide Concepts:
document.querySelector vs querySelectorAll
CSS selectors: nth-child()
DOM element innerHTML property
________________________________________
NEW QUESTION # 71
Which statement allows a developer to update the browser navigation history without a page refresh?
Answer: B
Explanation:
The correct answer is C.
The browser provides the History API through:
window.history
To add a new entry to the browser's session history without refreshing the page, JavaScript uses:
window.history.pushState(state, title, url);
So the valid statement is:
window.history.pushState(newStateObject, '', null);
This updates the browser history stack without forcing a full page reload. It is commonly used in single-page applications when changing views or routes dynamically.
The method accepts three arguments:
window.history.pushState(stateObject, title, url);
stateObject stores custom data associated with the history entry.
title is usually passed as an empty string because many browsers ignore it.
url optionally changes the displayed URL. Passing null means no new URL is provided.
Option A is incorrect because:
window.customHistory
is not the standard browser History API object.
Option B is incorrect because:
createState()
is not a valid History API method.
Option D is incorrect because:
updateState()
is not a valid History API method.
The correct browser API method is:
window.history.pushState()
Therefore, the verified answer is C.
NEW QUESTION # 72
......
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