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

I was hoping for something like:

NSString *string = @"hello bla bla";
NSLog(@"%d",[string containsSubstring:@"hello"]);

But the closest I could find was:

if ([string rangeOfString:@"hello"] == 0) {
    NSLog(@"sub string doesnt exist");
} 
else {
    NSLog(@"exists");
}

Anyway, is that the best way to find if a string contains another string?

1 upvote
  flag
I'd like to see it added as well, but in the meantime it's relatively easy to add it as a category on NSString. – isaac
2 upvote
  flag
Using if ([string rangeOfString:@"hello"] == 0) {...} there's a type mismatch error for NSRange and int. to fix that, you should change the line to the following: if ([string rangeOfString:@"hello"].length == 0) {...} – Neeku
1 upvote
  flag
iOS 8 adds containsString: and here is a minimally invasive way to add iOS 7 support petersteinberger.com/blog/2014/… – Steve Moser
upvote
  flag
I've been an iOS developer since the beginning and I constantly revisit this post for a quick copy paste. I can't seem to memorize this one. Most visited stackoverflow post in my history. – VaporwareWolf

18 Answers 11

up vote 2283 down vote accepted
NSString *string = @"hello bla bla";
if ([string rangeOfString:@"bla"].location == NSNotFound) {
  NSLog(@"string does not contain bla");
} else {
  NSLog(@"string contains bla!");
}

The key is noticing that rangeOfString: returns an NSRange struct, and the documentation says that it returns the struct {NSNotFound, 0} if the "haystack" does not contain the "needle".


And if you're on iOS 8 or OS X Yosemite, you can now do: (*NOTE: This WILL crash your app if this code is called on an iOS7 device).

NSString *string = @"hello bla blah";
if ([string containsString:@"bla"]) {
  NSLog(@"string contains bla!");
} else {
  NSLog(@"string does not contain bla");
}

👍

275 upvote
  flag
To make a case insensitive search use "if ([string rangeOfString:@"bla" options:NSCaseInsensitiveSearch].location != NSNotFound)" – Vanja
1 upvote
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@Dave DeLong I was just going to mention a Category that I created for this purpose before I read your edit to the answer! Since I am primarily a c# developer I am glad that they added a contains method to NSSTring. – dherrin79
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Why does the compiler don't say anything if my deployment target is iOS7 and I use containsString? – Ricardo
2 upvote
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And to further the point made by @Vanja : if you are going to use the [string containsString] shortcut code that was introduced in iOS 8/Yosemite, you can use the following code for a case insensitive string: "[stringToSearch localizedCaseInsensitiveContainsString:string]", and this one if you want to do a case and diacritic insensitive search: "[stringToSearch localizedStandardContainsString:string]". – Scott Kohlert
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@ScottKohlert Careful, [stringToSearch localizedStandardContainsString:string] was introduced in iOS9. – Erzékiel
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Note that the expression [string rangeOfString:@"bla"].location != NSNotFound will be true when string is nil! – funroll
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To keep iOS7 support one can add containsString: dynamically, for iOS8+ this code won't do anything and genuine containsString: will be used. - (void)setupContainsString { SEL containsStringSelector = @selector(containsString:); IMP containsStringIMP = imp_implementationWithBlock(^(id _self, NSString *string) {\ NSRange range = [_self rangeOfString:string]; return range.length != 0; }); //The method is added only if class has no implementation of it class_addMethod([NSString class], containsStringSelector, containsStringIMP, "c@@:"); } – Kamil.S

NOTE: This answer is now obsolete

Create a category for NSString:

@interface NSString ( SubstringSearch )
    - (BOOL)containsString:(NSString *)substring;
@end

// - - - - 

@implementation NSString ( SubstringSearch )

- (BOOL)containsString:(NSString *)substring
{    
    NSRange range = [self rangeOfString : substring];
    BOOL found = ( range.location != NSNotFound );
    return found;
}

@end

EDIT: Observe Daniel Galasko's comment below regarding naming

13 upvote
  flag
+1 for clearer resulting code and reusability. I turned it into the one liner return [self rangeOfString:substring].location != NSNotFound; and included it in my refactoring library, es_ios_utils. github.com/peterdeweese/es_ios_utils – Peter DeWeese
4 upvote
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Looks like Apple likes your idea and added this feature in iOS 8 and OSx 10.10 (Yosemite) as @DaveDeLong mentioned in his answer. +1 – Islam Q.
5 upvote
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The cardinal rule for obj-c categories is to prefix the method name with your 3 letter module prefix. This is the perfect example since it now conflicts with the iOS 7 and 10.10 release – Daniel Galasko
NSString *myString = @"hello bla bla";
NSRange rangeValue = [myString rangeOfString:@"hello" options:NSCaseInsensitiveSearch];

if (rangeValue.length > 0)
{
    NSLog(@"string contains hello");
} 
else 
{
    NSLog(@"string does not contain hello!");
}

//You can alternatively use following too :

if (rangeValue.location == NSNotFound) 
{
    NSLog(@"string does not contain hello");
} 
else 
{
    NSLog(@"string contains hello!");
}

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"); 

An improved version of P i's solution, a category on NSString, that not only will tell, if a string is found within another string, but also takes a range by reference, is:

@interface NSString (Contains)
-(BOOL)containsString: (NSString*)substring
              atRange:(NSRange*)range;

-(BOOL)containsString:(NSString *)substring;
@end

@implementation NSString (Contains)

-(BOOL)containsString:(NSString *)substring
              atRange:(NSRange *)range{

    NSRange r = [self rangeOfString : substring];
    BOOL found = ( r.location != NSNotFound );
    if (range != NULL) *range = r;
    return found;
}

-(BOOL)containsString:(NSString *)substring
{
    return [self containsString:substring
                        atRange:NULL];
}

@end

Use it like:

NSString *string = @"Hello, World!";

//If you only want to ensure a string contains a certain substring
if ([string containsString:@"ello" atRange:NULL]) {
    NSLog(@"YES");
}

// Or simply
if ([string containsString:@"ello"]) {
    NSLog(@"YES");
}

//If you also want to know substring's range
NSRange range;
if ([string containsString:@"ello" atRange:&range]) {
    NSLog(@"%@", NSStringFromRange(range));
}

Here is a copy-and-paste function snippet:

-(BOOL)Contains:(NSString *)StrSearchTerm on:(NSString *)StrText
{
    return [StrText rangeOfString:StrSearchTerm 
        options:NSCaseInsensitiveSearch].location != NSNotFound;
}
upvote
  flag
May I know why I am downvoted ? It's a working code snippet – Durai Amuthan.H

Since this seems to be a high-ranking result in Google, I want to add this:

iOS 8 and OS X 10.10 add the containsString: method to NSString. An updated version of Dave DeLong's example for those systems:

NSString *string = @"hello bla bla";
if ([string containsString:@"bla"]) {
    NSLog(@"string contains bla!");
} else {
    NSLog(@"string does not contain bla");
}

With iOS 8 and Swift, we can use localizedCaseInsensitiveContainsString method

 let string: NSString = "Café"
 let substring: NSString = "É"

 string.localizedCaseInsensitiveContainsString(substring) // true
1 upvote
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This is good. No idea why they didn't have this method for ios 7 – Lucas
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@Lucas, because Swift launched with iOS 8.0. but with swift you can still support the devices with iOS 7. – Hemang

If you need this once write:

NSString *stringToSearchThrough = @"-rangeOfString method finds and returns the range of the first occurrence of a given string within the receiver.";
BOOL contains = [stringToSearchThrough rangeOfString:@"occurence of a given string"].location != NSNotFound;

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");
}
NSString *categoryString = @"Holiday Event";
if([categoryString rangeOfString:@"Holiday"].location == NSNotFound)
{
    //categoryString does not contains Holiday
}
else
{
    //categoryString contains Holiday
}

Please use this code

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

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.

try this,

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

In case of swift, this can be used

let string = "Package #23"
if string.containsString("Package #") {
    //String contains substring
}
else {
    //String does not contain substring
}

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");
}

If certain position of the string is needed, this code comes to place in Swift 3.0:

let string = "This is my string"
let substring = "my"

let position = string.range(of: substring)?.lowerBound

In Swift 4

let a = "Hello, how are you?"

a.contains("Hello") //true

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