In this question, we are asked to write a routine to convert an Arabic integer number (I’ll use number to save some typing) into Roman numerals. To better understand how a number can be represented in Roman numerals, I created below chart: From above chart, we can observe below patterns: …

In this question, we are given an array of integer nums and an integer target, and we are asked to return two distinct indices such that the numbers in those positions add up to be the target. …

When using UnoSSL to issue a free SSL certificate for my website, it asked me to verify my ownership of the domain first. While when adding the second TXT record, I met below issue, saying “A record with the specified name already exists”:

Var Using var declares either a locally(within function) scoped variable or a globally scoped variable. Scope When var is used outside a function, it declares a globally scoped variable. var a = 2; // globally scoped variable function foo() { console.log(a); } foo(); // prints out 2 console.log(window.a); // prints out 2 …

Typically you can invoke your API using a URL of the following format after deploying: https://api-id.execute-api.region.amazonaws.com/stage Even though the region and stage are relatively stable and easy to remember, the api-id is kinda like a random number for each API created and is really not user friendly when it comes…

Deploying a multi-page Gatsby app to Lambda can be tricky, as you may find that the root URL works fine, while it breaks as soon as you click on some internal link trying to navigate to a different page within your app. In this article, I will demonstrate how to…

I’m currently working on an API website that provides users with APIs to retrieve movie information in JSON format. The very first challenge I met when designing the overall architecture was how can I serve my front-end web pages together with backend APIs under the same URL, i.e. …

Connecting to DynamoDB from Lambda is even easier than you can think of. Firstly, you need to create an execution role which later you can attach to the lambda function. To do so: Login IAM, select Roles under Access management in the left sidebar, click on the Create role button. …

By default AWS managed policies like AmazonDynamoDBFullAccess and AmazonDynamoDBReadOnlyAccess allow corresponding rules to all tables in DynamoDB, while we may want to select specific access permissions and apply to a specific table/tables. This is where customer managed policies come into play. We can create a customized policy and attach it…