Summary

In this chapter, we dealt with the first two programming building blocks: variables and operators. Variables are special fields that have a name and contain values. We declare a variable by using one of the special variable-defining words: let, var, or const. Variables enable us to make our scripts dynamic, store values, access them later, and change them later. We discussed some primitive data types, including strings, numbers, Booleans, and Symbols, as well as more abstract types such as undefined and null. You learned how to determine the type of a variable using the typeof word. And you saw how you can convert the data type by using the built-in JavaScript methods Number(), String(), and Boolean().

Then we moved on and discussed operators. Operators enable us to work with our variables. They can be used to perform calculations, compare variables, and more. The operators we discussed included arithmetic operators, assignment operators, comparison operators, and logical...