CODEWITHSUNDEEP
objective-cmacoscocoa
User1234
User1234

Reputation: 2412

How to append NSString wiht number?

I'm new in Cocoa.

I have NSString - (e.g) MUSIC . I want to add some new NSString in Array, And want to check something like this

if MUSIC already contained in Array, add Music_1 , after Music_2 and so on.

So I need to be able read that integer from NSString, and append it +1 .

Thanks

Upvotes: 0

Views: 2566

Answers (4)

Parag Bafna
Parag Bafna

Reputation: 22930

For checking duplicate element in Array you can use -containsObject: method. 

[myArray containsObject:myobject];

If you have very big array keep an NSMutableSet alongside the array.Check the set for the existence of the item before adding to the array. If it's already in the set, don't add it. If not, add it to both.
If you want unique objects and don't care about insertion order, then don't use the array at all, just use the Set. NSMutableSet is a more efficient container.
For reading integer from NSString you can use intValue method. 

[myString intValue];

For appending string with number you can use - (NSString *)stringByAppendingString:(NSString *)aString or - (NSString *)stringByAppendingFormat:(NSString *)format ... method.

Upvotes: 1

beryllium
beryllium

Reputation: 29767

Check it out:

NSMutableArray *array = [NSMutableArray arrayWithObjects:@"123", @"qqq", nil];
NSString *myString = @"MUSIC";
NSInteger counter = 0;
if ([array containsObject:myString]){
    NSString *newString = [NSString stringWithFormat:@"%@_%d", myString, ++counter];
    [array addObject:newString];
}
else
    [array addObject:myString];

Upvotes: 1

colincameron
colincameron

Reputation: 2703

Use

NSString *newString = [myString stringByAppendingString:[NSString stringWithFormat:@"_%i", myInteger]];

if myString is "music", newString will be "music_1" or whatever myInteger is.

EDIT: I seem to have gotten the opposite meaning from the other answer provided. Can you maybe clarify what it is you are asking exactly?

Upvotes: 4

Matt Williamson
Matt Williamson

Reputation: 40193

Here's how you convert a string to an int

NSString *myStringContainingInt = @"5";
int myInt = [myStringContainingInt intValue];
myInt += 1;
// So on...

Upvotes: 0

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