3️⃣Operators
Fall 2023 | Vin Bui
Last updated
Fall 2023 | Vin Bui
Last updated
We have seen the four basic math operations in elementary school: addition, subtraction, multiplication, and division. In Swift, we can use operators to perform these operations.
The following lines are equivalent:
These operators are self-explanatory; however, if we were to take a closer look at the the line a = a / 10 we can notice that the output is 2 instead of 2.5. The reason for this is because the type of a is an Int. If we were to perform these operations on a, then we must also use an Int.
Then, how do we get the value 2.5? Because the type of a is an Int, then we must introduce a new variable of type Double or Float since we cannot change the type of a variable once initialized. We would also need to make sure that the values in which we apply these operators on must also be a Double or Float.
Let's take a look at the line Double(a). This is known as type casting. Because a is an Int and we needed a Double, Double(a) converts the value 2 to 2.0. Note that this does not change the type of a. It only produces a value to be used for that operation.
One more common operator we may see is the modulus operator (%). This is similar to the / operator except we return the remainder.
The following is a list of common operators that we are likely to use.
>
greater than
||
or
>=
greater than or equal to
&&
and
<
less than
!
not
<=
less than or equal to
==
equal to
!=
not equal to
String interpolation is a way of combining variables and constants inside a string. Take a look at this example:
Of course, we could have used the + operator to concatenate these strings together.
The problem with this approach is efficiency especially if we want to concatenate multiple variables. Another issue with using + is that Swift does not allow types such as Int or Float to be glued with a String.
We could cast age to a String but that would be expensive.
Using string interpolation is a lot more efficient and looks cleaner too!
