CODEWITHSUNDEEP
iosstringmacosswift
mr_ivan777
mr_ivan777

Reputation: 401

StringBetweenString function

I need to get substring between two strings from my text. For example, I have text "http://google.com" and I want to get substring between "://" and ".".

I don't know, how I can do that.

I try to use regular expressions, but I think, it's bad way.

Upvotes: 4

Views: 4682

Answers (4)

Fuzuli
Fuzuli

Reputation: 173

For swift 3.0:

let us = "http://example.com"
let range = us.range(of:"(?<=://)[^.]+(?=.com)", options:.regularExpression)
if range != nil {
    let found = us.substring(with: range!)
    print("found: \(found)") // found: example
}

Upvotes: 0

zaph
zaph

Reputation: 112855

A couple of options:

  1. Regular expressions work well. See ICU User Guide: Regular Expressions

    Example:

    let us = "http://google.com"
let range = us.rangeOfString("(?<=://)[^.]+(?=.)", options:.RegularExpressionSearch)
if range != nil {
    let found = us.substringWithRange(range!)
    println("found: \(found)") // found: google
}

    Notes:

        (?<=://) means preceded by ://  
    [^.]+    means any characters except .  
    (?=.)    means followed by .

  2. NSScanner is also a good method. See Apple's NSScanner Class Reference

    Example:

    let us = "http://google.com"
let scanner = NSScanner(string:us)
var scanned: NSString?

if scanner.scanUpToString("://", intoString:nil) {
    scanner.scanString("://", intoString:nil)
    if scanner.scanUpToString(".", intoString:&scanned) {
        let result: String = scanned as String
        println("result: \(result)") // result: google
    }
}

Upvotes: 15

DarkDust
DarkDust

Reputation: 92354

If your input is a valid URL, you can take advantage of the NSURL class to do the parsing for you:

var result : NSString?
let input = "http://test.com/blabla"

// Parse the string; might fail
let url : NSURL? = NSURL(string: input)

// Get the host part of the URL ("test.com")
let host = url?.host

// Split it up at the dots.
let hostParts = host?.componentsSeparatedByString(".")

// Assign the first part of the hostname if we were successful up to here.
if hostParts?.count > 0 {
    result = hostParts![0]
}

Bonus: ignore "www":

if hostParts?.count > 0 {
    if (hostParts![0] == "www" && hostParts!.count > 1) {
        result = hostParts![1]
    } else {
        result = hostParts![0]
    }
}

Upvotes: 1

Binarian
Binarian

Reputation: 12446

You can use the regular Expression

://.+.

it matches to

://google.

in this code:

var yourURL: NSString = "http://google.com" // this is your input and could be any URL
var regex: NSRegularExpression = NSRegularExpression.regularExpressionWithPattern("://.+\\.", options: NSRegularExpressionOptions.fromMask(UInt(0)), error: nil) // need double backspace because of backspace in String is \\ not \
var needleRange = regex.rangeOfFirstMatchInString(yourURL, options:NSMatchingOptions.Anchored, range: NSMakeRange(0, yourURL.length))
var needle: NSString = yourURL.substringWithRange(needleRange)

Now you can remove the first 3 symbols and the last one and you got

google

with this code:

import Foundation

var halfURL: NSString = "://google."
var prefix: NSString = "://"
var suffix: NSString = "."
var needleRange: NSRange =  NSMakeRange(prefix.length, halfURL.length - prefix.length -     suffix.length)
var needle: NSString = halfURL.substringWithRange(needleRange)
// needle is now 'google'

Upvotes: 2

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