替换出现的字符串模式

Question

So this is a string I get back from the server:

var arrayString = "IT34:1, IT35:2, IT36:1, IT35:3"

I want to get rid of any occurrences of ":1", ":2" and am using:

let cleanStr = arrayString.stringByReplacingOccurrencesOfString(":1", withString: "", options: NSStringCompareOptions.LiteralSearch, range: nil)

let cleanStr1 = cleanStr.stringByReplacingOccurrencesOfString(":2", withString: "", options: NSStringCompareOptions.LiteralSearch, range: nil)

And so on...

Which doesn't seem very efficient. Is it possible to accomplish this with just one .stringByReplacingOccurrencesOfString method? Like occurrences of ":(a number)"?

Answer 1

This can be done using regular expressions:

let string = "IT34:1, IT35:2, IT36:1, IT35:3"
var cleanStr = string
if let regex = NSRegularExpression(pattern: ":[0-9]", options:.CaseInsensitive, error: nil) {
    cleanStr = regex.stringByReplacingMatchesInString(string, options: nil, range: NSMakeRange(0, countElements(string)), withTemplate: "")
}
println(cleanStr)

---

And in Objective-C:

NSString *string = @"IT34:1, IT35:2, IT36:1, IT35:3";
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@":[0-9]" options:NSRegularExpressionCaseInsensitive error:nil];
NSString *newString = [regex stringByReplacingMatchesInString:string options:0 range:NSMakeRange(0, [string length]) withTemplate:@""];
NSLog(@"%@", newString);

Answer 2

I do not know the exact pattern of those ":1" thingies, but here's a solution you might fiddle with:

let cleanStr = ", ".join(arrayString.componentsSeparatedByString(", ").map { ($0 as NSString).substringToIndex(4) })

This solution will work as long as the ':1" things have one digit.

Here's a general solution:

let cleanStr = ", ".join(arrayString.componentsSeparatedByString(", ").map {
    ($0 as NSString).componentsSeparatedByString(":")[0] as String
})