Day 45

in #code7 years ago

February 27th, 2018

Hello! Today at the ES6 course by Wes Bos I learned about maps and weak maps.
Maps are like objects. They have key-value pair. You can call .has() and .delete() on them.
As well as loop over them in two ways.

      dogs.forEach((val, key) => console.log(val, key));

     for(const [key, val] of dogs) {
          console.log(key, val);
     }

Map-metadata:

You can use an object as a key. You can store metadata about an object. Weak-map does not have a size, and it isn't innumerable. Items get garbage collected.

        const weak = new WeakMap();

At the Web Development Bootcamp by Colt Steele I learned about the EJS Control Flow.

We have to wrap each JS line in the <% %> tags

         <% if(thingVar.toLowerCase === 'Aaron') { %>
             <p>GOOD CHOICE! </p>
               <% } %>

You have to take away the equal signs because there are two different types of tags

<%= %> - the value that is returned will be rendered to the page, added to the HTML
<% %> - there is a logic, loops, control flows we don't want to add it to the page

Using a loop

        app.get("/posts", function(req, res) {
              var posts = [
                 {title: "Post 1", author: "Suzy"},
                 {title: "My adorable pet bunny", author: "Charlie"},
                 {title: "Can you believe pomsky ", author: "Colt"}
              ];

         res.render("posts.ejs", {posts:posts});
      });

Cheers!

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