Link: Soni Frontend Document
Practice Verified Codes and Commands:
1. Promise.resolve and Promise.reject Polyfills:
[javascript]
// Promise.resolve polyfill
Promise.myResolve = function(value) {
if (value && typeof value.then === ‘function’) {
return value;
}
return new Promise(function(resolve) {
resolve(value);
});
};
// Promise.reject polyfill
Promise.myReject = function(reason) {
return new Promise(function(resolve, reject) {
reject(reason);
});
};
[/javascript]
2. Get Max Element from an Array (ES5):
[javascript]
const list = [1, 2, 3, 4, 5, 6, 7];
const maxElement = Math.max.apply(null, list);
console.log(maxElement); // Output: 7
[/javascript]
3. Sort an Array:
[javascript]
const arr = [3, 1, 4, 1, 5, 9, 2, 6, 5];
const sortedArr = arr.sort((a, b) => a – b);
console.log(sortedArr); // Output: [1, 1, 2, 3, 4, 5, 5, 6, 9]
[/javascript]
4. Validate an HTML String:
[javascript]
function validateHTML(html) {
const doc = new DOMParser().parseFromString(html, ‘text/html’);
return Array.from(doc.body.childNodes).some(node => node.nodeType === 1);
}
console.log(validateHTML(‘
‘)); // Output: true
[/javascript]
5. Implement JSON.parse():
[javascript]
function myJSONParse(jsonString) {
return eval(‘(‘ + jsonString + ‘)’);
}
const obj = myJSONParse(‘{“name”: “John”, “age”: 30}’);
console.log(obj); // Output: { name: ‘John’, age: 30 }
[/javascript]
What Undercode Say:
The ServiceNow interview experience shared by Shubham Soni provides a deep dive into the challenges faced by frontend engineers during technical interviews. The questions range from basic JavaScript concepts like `Promise.resolve` and `Promise.reject` to more complex tasks such as implementing `JSON.parse()` and validating HTML strings. These questions test not only theoretical knowledge but also practical coding skills, which are crucial for frontend roles.
For those preparing for similar interviews, it’s essential to master JavaScript fundamentals, including ES5 and ES6 features, array manipulations, and DOM operations. Additionally, understanding bit manipulation and sorting algorithms can give you an edge in solving DSA-related questions.
Here are some Linux and Windows commands that can aid in your preparation:
- Linux Commands:
grep: Search for patterns in files.awk: Pattern scanning and processing language.sed: Stream editor for filtering and transforming text.curl: Command-line tool for transferring data with URLs.jq: Lightweight and flexible command-line JSON processor.Windows Commands:
findstr: Search for strings in files.powershell: Task automation and configuration management framework.netstat: Display network connections, routing tables, and interface statistics.tasklist: Display a list of currently running processes.ipconfig: Display all current TCP/IP network configuration values.
For further reading and practice, consider exploring the following resources:
- JavaScript MDN Docs
- LeetCode for DSA practice.
- Frontend Masters for advanced frontend courses.
By combining theoretical knowledge with practical coding exercises, you can enhance your problem-solving skills and increase your chances of success in technical interviews. Keep practicing, and don’t hesitate to explore additional resources to strengthen your understanding of frontend development concepts.
References:
Hackers Feeds, Undercode AI
