May 2018
Intermediate to advanced
376 pages
9h 22m
English
Content preview from Get Programming with JavaScript Next
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Lesson 5. Declaring constants with const
After reading lesson 5, you will
- Understand what constants are and how they work.
- Know when to use constants.
The keyword const stands for constant, as in never changing. Many programs have values that never change, whether by intention or by happenstance. Values declared with const, referred to as constants, have the same characteristics as those declared with let, which you learned about in the previous chapter, with the additional feature of reassignment being forbidden.
Consider this
Consider the following switch statement, which uses flags to determine what type of action is being performed. The uppercasing of ADD_ITEM and DEL_ITEM indicates that these are values that are never expected ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.