How to provide Default Values for AWS CloudFormation Parameters
AWS CloudFormation is very useful for creating template-able infrastructure definitions.
One of the sections of a template, is the Input Parameters, …
Technical Articles
In-depth guides, insights, and best practices for modern software engineering
How to Validate an AWS CloudFormation Template
The AWS CLI comes with a useful subcommand to validate a CloudFormation template.
This catches syntax errors and basic structural issues before you …
Read Article →How to Reverse Sort Integers in Go
The challenge
The two oldest ages function/method needs to be completed. It should take an array of numbers as its argument and return the two highest …
Read Article →How to view the Encoded Authorization Failure Message in AWS
You may come across a message that reads similar to the following:
<meta charset="utf-8">Encoded authorization failure message
A full …
Read Article →How to run/execute a program from Terraform
If you need to run a local application from your Terraform scripts, you can call out to the provisioner local-exec and issue the command syntax: …
How to script AWS AppStream 2.0 ImageBuilder
AppStream (2.0) is a fully managed non-persistent desktop and application service for remotely accessing your work.
The ImageBuilder forms the first …
How to Reimplement the Unix Uniq Command in Golang
The challenge
Implement a function which behaves like the uniq command in UNIX.
It takes as input a sequence and returns a sequence in which all …
Read Article →How to install GraalVM on Mac
Install GraalVM with Homebrew
Homebrew is the preferred way to install anything on your Mac.
brew install graalvm/tap/graalvm-ce-java17
Install …
Read Article →How to Generate Random Integers with a Range in Java
Java comes with many different ways to generate random integers, even if you need to specify a lower and upper bound to constrain your required value …
Read Article →How to create ArrayList from Array in Java
The problem
If you have a traditional array, that looks something like the following:
A[] array = {new A(1), new A(2), new A(3)};
And you would like …
Read Article →How to Generate a Random AlphNumeric String in Linux/MacOS
If you need to generate a random AlphaNumeric string from the Linux/MacOS Command-Line, then you can use the following script:
dd if=/dev/random bs=8 …How to check if a string is empty in Go
If you need to check if a string is empty in Go, then there are two possible ways to immediately verify this:
Option 1 – Compare the length:
if len(s) …How to read a file line by line in Go
If you need to read a file line by line in Go, then you can use the bufio package as follows:
package main
import (
"bufio" …Floating-point Approximation in Golang
The challenge
Consider the function
f: x -> sqrt(1 + x) - 1 at x = 1e-15.
We get: f(x) = 4.44089209850062616e-16
This function involves the …
Read Article →All the Ways to Divide an Array in Two in Golang
The challenge
Write a function partlist that gives all the ways to divide an array of at least two elements into two non-empty parts.
- Each two non …
How to check if a file exists in Go
If you need to check if a file exists using Go, then you can use one of the following methods, depending on the version of Go you may be using.
If you …
Read Article →How to convert a string value to an int in Go
If you need to convert a string to an int in Go, then you should use the strconv.Atoi function:
package main
import (
"strconv" …How to convert an int value to string in Go
If you need to convert an int to a string in Go, then you should use the strconv.Itoa function:
package main
import (
"strconv" …How to Efficiently Concatenate Strings in Go
If you are using a version of Go >= 1.10, then you should be using the newer strings.Builder pattern as follows:
package main
import ( …How to check if a map contains a key in Go
If you have a map in Go and want to only perform an action if it contains a certain key, then you can do so easily:
if val, ok := …How to Remove all Vowels from a String in Java
The challenge
Remove all vowels from the string.
Vowels:
a e i o u
A E I O U
The solution in Java code
Option 1:
public class VowelRemoval {
public …How to Loop Forever in Golang
If you need to loop forever, or infinitely, in your Go code, then you have 2 options:
Option 1:
for {
// your code here
}
Option 2:
for true {
// …Understanding For Loops in Golang
In Golang a for loop is a way to loop through an iterable.
The most basic For Loop
i := 0
for i <= 3 {
i = i + 1
}
A classic For Loop
for i := 7; …[Solved] go mod init: modules disabled by GO111MODULE=off
You’ve probably just tried to initialise a new Go module, and received the following error:
go mod init: modules disabled by GO111MODULE=off; …