Skip to main content

JavaScript Basic: For Loop Study Note


For loop is another way of repeating code.

for( initial; condition; step) {
//run some code
}

As you see, for loop includes three part:

  • The first part is the initialize where we declare a variable and set it to some initial value.
  • The second part is condition which is when this loop should keep running.
  • The last part is step, so what do we do at the end of every iteration.
I would like to share two examples from the course:

Print numbers from 0 to 5 with a for loop

I write the for loop in the console. There are three part in the for loop: 

1. Initial: count start from 0 (count = 0) 
2. Condition: run the code until the count is less than 6 ( count < 6)
3. Step: count incrementally

The result list 0 to 5.

Print each character in a string with a for loop



1. Initial: list the character from the beginning (start 0) 
2. Condition: run the code until it end by the string length 
3. Step: list all the characters in order

The result list each character for "hello"

Comments

Popular posts from this blog

Intermediate Express.js: How To Add Styles & Partials in EJS File?

So far, we only have simple HTML tags and ejs tags in each ejs file. Every template page has no style at all. And the basic HTML header and footer are also missing. Today, I learned how to add styles and partials in ejs file. Link Style Step One: Touch a Separate CSS file I create a new directory "Style" under the "EJSDemo" directory, then I add a new CSS file "app.css" inside "Style" folder. Step Two: Add app.use(express.static()) in the app.js I add app.use(express.static("style")) in the "app.js". This will tell Express.js to serve the content of "Style" directory. Step Three: Write styles in CSS file I simple give body an orange background color and set text color to be grey. Step Four: Link to CSS file in the EJS file I just add <link> tag to link the "app.css" file on the top of the h1 tag in each ejs template. As the result, when I run the app and...

Intro to Backend: Is Browser The Only Place To Send HTTP Request?

Today,  I begin to learn the second part of web develop course: backend. Frontend is the stuff that we can see and interactive with, such as HTML, CSS, and JS. We can type our code, style our page, or write some function to make interaction. However, backend is everything else. For example, we type Target web address in the Internet Browser. As we hit "enter", there are a few steps to go through: 1. The HTTP request is sent to a particular server's IP address. 2. The server figures out what to send us 3. It sends a HTTP response back to us Those process we are hard to see, and it happens in less than one second. The instructor said that the browser is not the only place to send the HTTP request, and there are so many choices out there. In this learning course, we are going to use Postman App . Postman allows us to make HTTP requests and viewer responses. It is really for developers to understand how things are working or debug something. In the P...

Seven RESTful Routes You Should Know!

I have been followed the course to develop several app projects. They all follow the RESTful route pattern. Today, I learned many key points about RESTful and would like to share my study note here. What Is REST? REST stands for representational state transfer. I don't know what does this mean, but it is not important right now. You just need to know that REST is just a pattern for defining our routes. What's The Point Of REST? The important things for us is to define what REST is. REST is a way of mapping HTTP routes and CRUD functionality together. By the way CRUD stands for Create, Read, Update, and Destroy. The point of REST is that we don't do whatever we want. Instead, we follow a pattern. It is also more reliable so that if we are interacting with a restful API, it follows a particular pattern. Seven RESTful Routes The course lists the seven route table. It just acts as a pattern that we can fill in the blanks when we develop our own App. screen...