Swift 5 replacingOccurrences multiple elements

Question

let osetx = "01et"

I want to replace "e" with "11" and "t" with "10." What is the syntax to do that by calling the function only once?

let newOsetx = osetx.replacingOccurrences(of: "e", with: "11")

The above only replaces one of the 2 elements, obviously.

THANK YOU pawello2222 for the syntax in the comments.

osetx.replacingOccurrences(of: "e", with: "11").replacingOccurrences(of: "t", with: "10")

Answer 1

xTwisteDx’s answer is correct. Just chain your replacingOccurrences calls.

But just a stylistic observation: Frequently, when chaining a bunch of calls like this, we might break it into separate lines, e.g.

let newOsetx = osetx
    .replacingOccurrences(of: "e", with: "11")
    .replacingOccurrences(of: "t", with: "10")

When you're doing a bunch of replacements, that can make it a little more easy to read the code at a glance.

---

If you are doing more than two or three replacements, you might consider using some looping pattern. For example, you could use an array of tuples representing the search and replace strings:

let replacements = [
    ("e", "11"),
    ("t", "10")
]

Then you can loop through them, performing the replacements:

var newOsetx = osetx

for (searchString, replacement) in replacements {
    newOsetx = newOsetx.replacingOccurrences(of: searchString, with: replacement)
}

Or you can use reduce:

let newOsetx = replacements.reduce(osetx) { string, replacement in
    string.replacingOccurrences(of: replacement.0, with: replacement.1)
}

Answer 2

You can chain your method calls. replacingOccurrences is a string method that does something to the string, but it returns a string. As a result, you can chain the result of the first and then do the same again. In fact you can do this an indeterminate amount of times, however there are better ways to do it.

newOsetx = osetx.replacingOccurrences(of: "e", with: "ll").replacingOccurrences(of: "t", with: "10")

Another option would be to do it like this.

newOsetx = osetx.replacingOccurrences(of: "e", with: "ll")
let finalOsetX = newOsetx.replacingOccurrences(of: "t", with: "10")

In general have a look at the returned type of a method, it shows up in the drop down window. That returned type will have methods that it can be used with as well.