Question

We looked at four types of JavaScript values in this chapter: numbers, strings, Booleans, and undefined values.

Such values are created by typing in their name ( true , null ) or value ( 13 , "abc" ). You can combine and transform values with operators. We saw binary operators for arithmetic ( + , - , * , / , and % ), string concatenation ( + ), comparison ( == , != , === , !== , < , > , <= , >= ), and logic ( && , || ), as well as several unary operators ( - to negate a number, ! to negate logically, and typeof to find a value’s type) and a ternary operator ( ?: ) to pick one of two values based on a third value.

This gives you enough information to use JavaScript as a pocket calculator, but not much more. The next chapter will start tying these expressions together into basic programs.

This is a book about getting computers to do what you want them to do. Computers are about as common as screwdrivers today, but they contain a lot more hidden complexity and thus are harder to operate and understand. To many, they remain alien, slightly threatening things.