Hello, Space Explorer! Today, we're going to delve into the TypeScript data types. Think of data types as different celestial objects in our universe, each with its unique properties and uses. We'll explore five core TypeScript types — Number
, String
, Boolean
, Void
, and Undefined
.
In TypeScript, types are categorized based on their characteristics. Understanding this is akin to realizing that Earth is a planet, not a star or an asteroid. This knowledge helps us predict behaviors in different situations.
First, we're going to uncover numerical values through the Number
type, which stores numbers such as 10
(integer numbers) or -2.19
(floating point numbers, i.e., numbers with a decimal point). Let's visualize it:
Upon running this code, you'll see 8
and 3.52
printed — these are the values of our declared numPlanets
and planetWeight
variables.
Next, we'll traverse the textual space with the String
type, which represents any text data. Let's create planetName
and assign it the value "Earth".
Seeing "Earth"
printed to the console illustrates how the String
variable planetName
works!
In the TypeScript universe, the Boolean
type is like binary stars, manifesting as either true
(correct, valid) or false
(incorrect, invalid). These are often used in programming to make decisions. Let's see it in action:
When you run this code, true
and false
are printed, which indicates that the earthIsAPlanet
is true
and appleIsAPlanet
is false
.
In TypeScript, void
is used when there's no data. This type is usually used as the return type of functions that do not return anything. We'll learn more about functions soon.
When this function is run, it prints Hello
and does not return anything.
undefined
, a designation for a variable that is declared but not assigned a value, is akin to spotting a planet about which we know nothing.
When you run this code, undefined
is printed, indicating that newPlanet
has been declared but not assigned a value.
Great job! We've journeyed through TypeScript types: Number
, String
, Boolean
, Void
, and Undefined
. Now, let's progress toward practice exercises to reinforce this knowledge. As you learn more with each exercise, you'll gain a more profound understanding of TypeScript types. Remember, practice is key! Let's continue exploring!
