How to see if an NSString starts with a certain other string?

I am trying to check to see if a string that I am going to use as URL starts with http. The way I am trying to check right now doesn't seem to be working. Here is my code:

NSMutableString *temp = [[NSMutableString alloc] initWithString:@"http://"];
if ([businessWebsite rangeOfString:@"http"].location == NSNotFound){
    NSString *temp2 = [[NSString alloc] init];
    temp2 = businessWebsite;
    [temp appendString:temp2];
    businessWebsite = temp2;
    NSLog(@"Updated BusinessWebsite is: %@", businessWebsite);
}

[web setBusinessWebsiteUrl:businessWebsite];

Any ideas?

Solution 1:

Try this: if ([myString hasPrefix:@"http"]).

By the way, your test should be != NSNotFound instead of == NSNotFound. But say your URL is ftp://my_http_host.com/thing, it'll match but shouldn't.

Solution 2:

I like to use this method:

if ([[temp substringToIndex:4] isEqualToString:@"http"]) {
  //starts with http
}

or even easier:

if ([temp hasPrefix:@"http"]) {
    //do your stuff
}

Solution 3:

If you're checking for "http:" you'll probably want case-insensitive search:

NSRange prefixRange = 
    [temp rangeOfString:@"http" 
                options:(NSAnchoredSearch | NSCaseInsensitiveSearch)];
if (prefixRange.location == NSNotFound)

Solution 4:

Swift version:

if line.hasPrefix("#") {
  // checks to see if a string (line) begins with the character "#"
}