Swift replace occurrence of string with condition - swift

Question

I have string like below
<p><strong>I am a strongPerson</strong></p>
I want to covert this string like this
<p><strong>I am a weakPerson</strong></p>
When I try below code
let old = "<p><strong>I am a strongPerson</strong></p>"
let new = old.replacingOccurrences(of: "strong", with: "weak")
print("\(new)")
I am getting output like
<p><weak>I am a weakPerson</weak></p>
But I need output like this
<p><strong>I am a weakPerson</strong></p>
My Condition here is
1.It has to replace only if word does not contain these HTML Tags like "<>".
Help me to get it. Thanks in advance.

Answer 1

You can use a regular expression to avoid the word being in a tag:
let old = "strong <p><strong>I am a strong person</strong></p> strong"
let new = old.replacingOccurrences(of: "strong(?!>)", with: "weak", options: .regularExpression, range: nil)
print(new)
I added some extra uses of the word "strong" to test edge cases.
The trick is the use of (?!>) which basically means to ignore any match that has a > at the end of it. Look at the documentation for NSRegularExpression and find the documentation for the "negative look-ahead assertion".
Output:
weak <p><strong>I am a weak person</strong></p> weak

Answer 2

Try the following:
let myString = "<p><strong>I am a strongPerson</strong></p>"
if let regex = try? NSRegularExpression(pattern: "strong(?!>)") {
let modString = regex.stringByReplacingMatches(in: myString, options: [], range: NSRange(location: 0, length: myString.count), withTemplate: "weak")
print(modString)
}