Check if passed argument value is nil or empty

Question

I am trying to re-write the C# code which i have wrote previously to Swift.

public static string Right( string value, int length)
{
    if (String.IsNullOrEmpty(value)) return string.Empty;
    return value.Length <= length ? value : value.Substring(value.Length - length);
}

I am not able to write if statement effectively in swift.

Possible duplicate of [Check empty string in Swift?](https://stackoverflow.com/questions/24133157/check-empty-string-in-swift) — Alen Genzić, May 30 '19 at 12:52

PGDev · Answer 1 · 2019-05-30T13:21:28.617

In Swift you can write,

func right(value: String, length: Int) -> String {
    if value.count <= length {
        return value
    } else {
        let index = value.index(value.startIndex, offsetBy: value.count-length)
        return String(value[..<index])
    }
}

There is no need to check for empty string. It will be covered in the else condition itself.

Example:

right(value: "abcdefgh", length: 3) //abcde

score 1 · Answer 2 · answered May 30 '19 at 13:36

It can be done as simple as that:

func right(value: String, length: Int) -> String {
    guard value.count > length, length > 0 else { return value }
    return String(
        value.dropLast(length) // we just drop `length` number of elements from the end
    )
}

score 0 · Accepted Answer · answered May 30 '19 at 15:38

0

Using prefix and ?: as a one-liner

func right(value: String, length: Int) -> String {
    return value.count > length ? String(value.prefix(value.count - length)) : value
}

answered May 30 '19 at 15:38

Joakim Danielson

43,251
5
22
52

Check if passed argument value is nil or empty

3 Answers3