Data Types
Rust's design requires every value have a "type" assigned to. The "type" of a value is what you'd used to answer a question about what kind of thing it is. For example, if you were asking someone about their dog:
What kind of dog is Charlie?
A golden retriever
And, in a similar manner when discussing a Rust program:
What type of variable is alfa?
A number with a decimal point
Except we wouldn't use the term "a number with a
decimal point". We'd use f32
. That's what Rust
uses to set the type of a value to a "floating-point
number" (which is a number that has a decimal point
compared to an "integer" which doesn't).
As we saw in the previous chapter, types are assigned
to variables when they are created. We used i32
in the prior examples for integers. We could have used
f32
for floating-point numbers just as easily:
For example:
SOURCE CODE
fn main() {
let alfa: f32 = 3.4;
println!("Value {}", alfa);
}