What does the express.json() middleware do in an Express application?
- Parses JSON data from incoming requests
- Sends JSON responses to clients
- Creates a JSON file in the server directory
- Validates JSON data in requests
The express.json() middleware in Express.js is used to parse JSON data from incoming requests. It parses the request body and makes the JSON data available for further processing in your application. The other options do not accurately describe the purpose of this middleware.
What are the security implications of using third-party libraries and how can they be mitigated?
- Third-party libraries may introduce vulnerabilities
- Third-party libraries always enhance security
- Third-party libraries have no impact on security
- Third-party libraries only affect performance
Using third-party libraries in software development can introduce security vulnerabilities. These libraries may contain known or unknown security flaws. To mitigate these risks, developers should regularly update libraries to the latest secure versions, use security scanning tools, and perform code reviews to identify and address potential vulnerabilities.
What is the primary purpose of indexing in databases?
- Speed up data retrieval
- Reduce storage space
- Enhance data security
- Sort data alphabetically
The primary purpose of indexing in databases is to speed up data retrieval. Indexes provide a quick way to locate specific rows in a large database table, improving query performance. While indexing may use additional storage, its main benefit is optimizing data access.
You have been tasked with securing a web application against XSS and CSRF attacks. What combination of security headers, practices, and designs would you use to mitigate the risk of these attacks?
- Implement Content Security Policy (CSP) headers and use anti-CSRF tokens.
- Disable browser same-origin policies for enhanced security.
- Store sensitive data in cookies without encryption.
- Allow inline scripts and styles for flexibility.
Option (1) is correct. Implementing Content Security Policy (CSP) headers and using anti-CSRF tokens are effective measures to mitigate XSS and CSRF attacks. Options (2) and (4) are insecure practices that would increase vulnerability. Option (3) is incorrect as sensitive data should be encrypted, not stored in cookies without protection.
In Express.js, sensitive static files can be secured by implementing access restrictions on the static files directory.
- Size
- Permissions
- File
- Path
Implementing access restrictions, typically using file permissions, helps secure sensitive static files in Express.js. By restricting who can read or modify these files, you can prevent unauthorized access to sensitive data.
Why is it important to optimize database queries in a Node.js application?
- To improve application performance
- To increase database security
- To reduce the number of tables in the database
- To add more features to the application
Optimizing database queries is crucial in Node.js to improve application performance. Inefficient queries can lead to slower response times, increased resource consumption, and a poor user experience.
Which HTTP header is crucial for handling CORS in web applications?
- Access-Control-Allow-Origin
- Cross-Domain-Allow
- Allow-Access-Control
- Origin-Control-Allow
The crucial HTTP header for handling CORS in web applications is Access-Control-Allow-Origin. This header specifies which domains are allowed to access resources on the server. It plays a central role in configuring the CORS policy for a web server.
In JavaScript, every function has a ______ property that points to the object it was created from.
- object
- constructor
- instance
- funcObj
Every function in JavaScript has a constructor property that points to the object (constructor) it was created from. This property is useful for identifying the constructor function of an object.
In Mongoose, how can you ensure data integrity and validate schema definitions for embedded documents?
- Using the required property in the schema
- Using the validate method in the schema
- Using the embedded keyword in the schema
- Using the unique property in the schema
In Mongoose, you can ensure data integrity and validate schema definitions for embedded documents by using the validate method in the schema. This method allows you to define custom validation logic. The required property specifies that a field is required but doesn't validate the schema. The embedded and unique options are not standard Mongoose properties.
Which method would you use to concatenate multiple buffers in Node.js?
- buffer.concat()
- buffer.join()
- buffer.append()
- buffer.merge()
To concatenate multiple buffers in Node.js, you should use the buffer.concat() method. The other options are not valid methods for buffer concatenation.