Question

I want to check if an NSString is a valid URL so I can parse it to an NSURL variable… is there an easy way to do this? 🙂

CRASH
For some reason the app crashes when checking…..

NSURL *shortURL = [[NSURL alloc] initWithString:data];
if(shortURL == nil)
{
    NSLog(@"INVALID");
}
else {
    NSLog(@"COOOL");
}

The console gives me this error…..

* Terminating app due to uncaught exception ‘NSInvalidArgumentException’, reason: ‘* -[NSURL initWithString:relativeToURL:]: nil string parameter’
2010-03-01 19:24:14.797 Snippety[8289:5e3b] Stack: (
8307803,
2419510843,
8391739,
8391578,
2898550,
3152497,
12262,
12183,
27646,
2662269,
2661144,
2454790485,
2454790162
)

Answer 1

Edit: the below answer is not true. (Apple docs: https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSURL_Class/index.html)

---

NSURL‘s URLWithString returns nil if the URL passed is not valid. So, you can just check the return value to determine if the URL is valid.

Example:

NSURL *url = [NSURL URLWithString:urlString];
if(url){ NSLog("valid"); }