How do I check if a string contains another string in Objective-C?

Question

How can I check if a string (NSString) contains another smaller string?

I was hoping for something like:

NSString *string = @\"hello bla         


        

Answer 1

So personally I really hate NSNotFound but understand its necessity.

But some people may not understand the complexities of comparing against NSNotFound

For example, this code:

- (BOOL)doesString:(NSString*)string containString:(NSString*)otherString {
    if([string rangeOfString:otherString].location != NSNotFound)
        return YES;
    else
        return NO;
}

has its problems:

1) Obviously if otherString = nil this code will crash. a simple test would be:

NSLog(@"does string contain string - %@", [self doesString:@"hey" containString:nil] ? @"YES": @"NO");

results in !! CRASH !!

2) What is not so obvious to someone new to objective-c is that the same code will NOT crash when string = nil. For example, this code:

NSLog(@"does string contain string - %@", [self doesString:nil containString:@"hey"] ? @"YES": @"NO");

and this code:

NSLog(@"does string contain string - %@", [self doesString:nil containString:nil] ? @"YES": @"NO");

will both result in

does string contains string - YES

Which is clearly NOT what you want.

So the better solution that I believe works is to use the fact that rangeOfString returns the length of 0 so then a better more reliable code is this:

- (BOOL)doesString:(NSString*)string containString:(NSString*)otherString {
    if(otherString && [string rangeOfString:otherString].length)
        return YES;
    else
        return NO;
}

OR SIMPLY:

- (BOOL)doesString:(NSString*)string containString:(NSString*)otherString {
    return (otherString && [string rangeOfString:otherString].length);
}

which will for cases 1 and 2 will return

does string contains string - NO

That's my 2 cents ;-)

Please check out my Gist for more helpful code.

Answer 2

Best solution. As simple as this! If you want to find a word or part of the string. You can use this code. In this example we are going to check if the value of word contains "acter".

NSString *word =@"find a word or character here";
if ([word containsString:@"acter"]){
    NSLog(@"It contains acter");
} else {
     NSLog (@"It does not contain acter");
}

Answer 3

First string contain or not second string,

NSString *first = @"Banana";
NSString *second = @"BananaMilk";
NSRange range = [first rangeOfString:second options:NSCaseInsensitiveSearch];

if (range.length > 0) {
    NSLog(@"Detected");
}
else {
    NSLog(@"Not detected");
}

Answer 4

If do not bother about case-sensitive string. Try this once.

NSString *string  = @"Hello World!";

if([string rangeOfString:@"hello" options:NSCaseInsensitiveSearch].location !=NSNotFound)
{
    NSLog(@"found");
}
else
{
    NSLog(@"not found");
}

Answer 5

Oneliner (Smaller amount of code. DRY, as you have only one NSLog):

NSString *string = @"hello bla bla";
NSLog(@"String %@", ([string rangeOfString:@"bla"].location == NSNotFound) ? @"not found" : @"cotains bla"); 

Answer 6

try this,

NSString *string = @"test Data";
if ([[string lowercaseString] rangeOfString:@"data"].location == NSNotFound) 
{
    NSLog(@"string does not contain Data");
}   
else 
{
    NSLog(@"string contains data!");
}