前端开发人员在线测试

A web app for a popular AI conference (conducted in New York, with attendees from around the world) uses a signup/login page before users can access their dashboard. The signup/login page uses a form for users to input details and submit. The details are then sent to the backend service for processing. All user actions are logged in a log server. Senior Frontend Engineer, Musk, observed patterns in the issues users are facing with the the web app. Here are the two common patterns that Musk observed in the issues that have been occurring for most users:

Which of the following should Musk do to enhance the user experience with the page?

A: Implement validation using JS event listeners on client-side (e.g., on input or change)
B: Utilize HTML5 built-in form validation attributes (e.g., required, pattern)
C: Use server-side validation and refresh the page on form submission
D: Use a serverless function that processes the user’s form details, saves the user’s entries in the database and responds with validation data

A senior front-end engineer is tasked with optimizing the loading speed of a web application. The current bottleneck is the large number of JavaScript files that must be downloaded before the application becomes interactive. The engineer noticed that the browser spends a lot of time parsing and executing the JS code before making the application interactive. Which of the following techniques should the engineer apply to address this issue?

Consider the following shorthand CSS example:

background: #f7f7f7 url(jolie.jpg) no-repeat scroll 0px 0px;

Which of the following show the individual background properties represented by the shorthand:

Our intern is writing a colorful blog post, and has written the following code. What colors will the sentences be?

A: Sentence 1 will be gray, Sentence 2 will be pink.
B: Both sentences will be gray.
C: Sentence 1 will be pink, Sentence 2 will be gray.
D: Both sentences will be pink.
E: The code does not make sense; will throw an error.

In the following HTML, what will be the color of link with class "mark"

Consider the following HTML and CSS:

Which additional CSS rule(s) will render the following image? Choose ALL that apply.

A:
div{
  flex-direction : column;
  align-items : center;
}

B:
div{
  flex-direction : row;
  align-items: center;
}

C:
div{
  flex-direction: column;
  justify-content: center;
}

D:
div{
  flex-direction: row;
  justify-content: center;
}

What will the following code output?

A: 24 after 5 seconds and after another 5 seconds, another 24
B: 24 followed by another 24 immediately
C: 24 immediately and another 24 after 5 seconds
D: After 5 seconds, 24 and 24
E: Undefined
F: NaN
G: None of these

Review the following JavaScript code and pick the correct options: 

Assume that the API returns a successful 200 response code and a JSON object as the response body. What would the value of ‘a’ be after the code is executed?

What will the output of the following JavaScript code be?

What does the following code output? 

What does the following JS code output?

We want to register students for the next semester. All students have a receipt which shows the amount pending for the previous semester. A positive amount (or zero) represents that the student has paid extra fees, and a negative amount represents that they have pending fees to be paid. The students are in a queue for the registration. We want to arrange the students in a way such that the students who have a positive amount on the receipt get registered first as compared to the students who have a negative amount. We are given a queue in the form of an array containing the pending amount.

For example, if the initial queue is [20, 70, -40, 30, -10], then the final queue will be [20, 70, 30, -40, -10]. Note that the sequence of students should not be changed while arranging them unless required to meet the condition.

⚠️⚠️⚠️ Note:
- The first line of the input is the length of the array. The second line contains all the elements of the array.
- The input is already parsed into an array of "strings" and passed to a function. You will need to convert string to integer/number type inside the function.
- You need to "print" the final result (not return it) to pass the test cases.

For the example discussed above, the input will be:
5
20 70 -40 30 -10

Your code needs to print the following to the standard output:
20 70 30 -40 -10

A manager hires a staff member to keep a record of the number of men, women, and children visiting the museum daily. The staff will note W if any women visit, M for men, and C for children. You need to write code that takes the string that represents the visits and prints the count of men, woman and children. The sequencing should be in decreasing order. 

Example:

Input:
WWMMWWCCC

Expected Output: 
4W3C2M

Explanation: 
‘W’ has the highest count, then ‘C’, then ‘M’. 

⚠️⚠️⚠️ Note:
- The input is already parsed and passed to a function.
- You need to "print" the final result (not return it) to pass the test cases.
- If the input is- “MMW”, then the expected output is "2M1W" since there is no ‘C’.
- If any of them have the same count, the output should follow this order - M, W, C.