ls displays the list of your current directory cd + folder name gets you into the desired folder cd ~ goes back to the home directory mkdir makes a folder control + a goes to the beginning of the command control + u clear the command line control + e : goes to the end of the command touch filename: creates a new file open filename: opens the file rm filename: removes the file rm * : removes all files in your current directory

Imperative programming is you tell you program imperative instructions on what to do, when to do, and how to do it. Example for imperative programming language include Java, C, Python, and Ruby. Declarative programming is what you want the program to achieve. It’s up to the programming language’s implementation and…

Unlike other programming languages, Ruby has p, print, puts to print out information to the command line. For Ruby beginners, it might be a little bit confusing to figure out when to use what. print calls to_s on the object, it doesn’t append a new line. > print 1,2,3 123 => nil puts call to_s and add a new line to the output > puts 1,2,3 1 2 3 => nil p calls inspect method and adds a new line. p is more useful for debugging, as it returns the original data type.

Leetcode 42 Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it can trap after raining.

leetcode 48 You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise). You have to rotate the image in place, which means you have to modify the input 2D matrix directly. DO NOT allocate another 2D matrix and do the rotation. …

A mini project with Python to automate your work My friend reached out to me yesterday asking me if I can generate emails for him. His request is simple. He wants to register a new Gmail account, the format is “Lin****@gmail.com”. The four stars are random numbers. His last name…

After I’ve finally deployed my app in Heroku, I decided to write a blog to go over my very first JS project. Hopefully it gives you an idea on how to start with your project. My initial idea was to make a to-do app, but as I was told by…

When you start to work with Javascript as a new developer, the developer tool console.log() becomes your best friend. But, besides console.log(), there are many more tools that you can use. This post is intended to be useful for beginners. Do you know you can actually style you console.log()…

Intersection of Two Array Question: Given two arrays, write a function to compute their intersections. Noted, each element in the result should appear as many times as it shows in both arrays, and the result can be in any order. Examples: The naive way to solve this problem is to iterate through the first…