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?

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.

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
}

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)

This is my solution to the problem. It will remove the letters that are not necessary and is case insensitive.

- (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView {
return [self generateSectionTitles];
}

-(NSArray *)generateSectionTitles {

NSArray *alphaArray = [NSArray arrayWithObjects:@"A", @"B", @"C", @"D", @"E", @"F", @"G", @"H", @"I", @"J", @"K", @"L", @"M", @"N", @"O", @"P", @"Q", @"R", @"S", @"T", @"U", @"V", @"W", @"X", @"Y", @"Z", nil];

NSMutableArray *sectionArray = [[NSMutableArray alloc] init];

for (NSString *character in alphaArray) {



if ([self stringPrefix:character isInArray:self.depNameRows]) {
[sectionArray addObject:character];
}

}

return sectionArray;

}

-(BOOL)stringPrefix:(NSString *)prefix isInArray:(NSArray *)array {

for (NSString *str in array) {

//I needed a case insensitive search so [str hasPrefix:prefix]; would not have worked for me.
NSRange prefixRange = [str rangeOfString:prefix options:(NSAnchoredSearch | NSCaseInsensitiveSearch)];
if (prefixRange.location != NSNotFound) {
return TRUE;
}

}

return FALSE;

}

- (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSString *)title atIndex:(NSInteger)index {

NSInteger newRow = [self indexForFirstChar:title inArray:self.depNameRows];
NSIndexPath *newIndexPath = [NSIndexPath indexPathForRow:newRow inSection:0];
[tableView scrollToRowAtIndexPath:newIndexPath atScrollPosition:UITableViewScrollPositionTop animated:NO];

return index;
}

// Return the index for the location of the first item in an array that begins with a certain character
- (NSInteger)indexForFirstChar:(NSString *)character inArray:(NSArray *)array
{
NSUInteger count = 0;
for (NSString *str in array) {

//I needed a case insensitive search so [str hasPrefix:prefix]; would not have worked for me.
NSRange prefixRange = [str rangeOfString:character options:(NSAnchoredSearch | NSCaseInsensitiveSearch)];
if (prefixRange.location != NSNotFound) {
return count;
}
count++;
}
return 0;
}

**Swift version:**

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