IOS : containsObject Check for String

Question

i have Array of String like: Array = P123, P234, P543, P678

and i have string like P12300.(this can be same string inside array or without trailling zeros).

i was using containsObject

if(Array containsObject: P123)    ==> TRUE
if(Array containsObject: P23400)  ==> FALSE
if(Array containsObject: P1230)    ==> FALSE

is there any better way to compare string so that above ALL case's will be true?

at present i am using containsObject, and i am not getting desired result as condition will be only true for exact same string.

Please let me know good way..

Nirav D · Accepted Answer · 2017-06-07T09:43:43.163

6

Objective c

You can use NSPredicate for that.

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"self BEGINSWITH[c] %@", @"P123"];
NSArray *filterArray = [yourArray filteredArrayUsingPredicate: predicate];
if (filterArray.count > 0) {
    print("Contains")
}
else {
    print("Not")
}

Swift

Yes, You can check like that, you need to simply use contains(where:) for that.

if yourArray.contains(where: { $0.hasPrefix("P123") }) {
    print("Contains")
}
else {
    print("Not")
}

Edit: If you want to ignore the trailing zeros you can truncate the trailing zero before comparing it with array.

NSString *str = @"P12300";
NSRange range = [str rangeOfString:@"0*$" options:NSRegularExpressionSearch];
str = [str stringByReplacingCharactersInRange:range withString:@""];
NSLog(@"%@", str); //P123
//Now use this str to check its inside the array or not
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"self BEGINSWITH[c] %@", str];

edited Jun 07 '17 at 09:43

answered Jun 07 '17 at 06:58

Nirav D

71,513
12
161
183

yourArray.contains there is no contains property ? – user2813740 Jun 07 '17 at 07:00
@user2813740 This is Swift, I haven't check question is tagged with Objective C let me edit my answer. – Nirav D Jun 07 '17 at 07:00
2

@AbhishekMitra, this is the best part of StackOverflow and we all developers. Keep adding good answers to help the community. – Hemang Jun 07 '17 at 07:03
@Hemang Yes, Thats why I up voted his ans immediately. And it is fun too. :) – Abhishek Mitra Jun 07 '17 at 07:06
1

@AbhishekMitra, I too. ;) – Hemang Jun 07 '17 at 07:07
what if i have array = P123,P234 and i have to check for P12300 – user2813740 Jun 07 '17 at 07:27
@user2813740 You mean you want to compare it by ignoring the suffix `0's` ? – Nirav D Jun 07 '17 at 08:42
yes .... as Array comping from DB i do not have Control over it.... String is by scanning so i need to check if (array P123 , P234) is having P12300. ignore zero. – user2813740 Jun 07 '17 at 09:37
@user2813740 Check the edited answer, also I have changed in predicate with `BEGINSWITH` instead of `contains` make it like this and you all set to go. – Nirav D Jun 07 '17 at 09:40
@user2813740 Welcome mate :) – Nirav D Jun 07 '17 at 11:16

score 1 · Answer 2 · answered Jun 07 '17 at 06:59

1

You may want to use [string1 isEqualToString:string2]

In that case it will evaluate to true only if strings are equal.

You may also use containString method. You may find this link helpfull.

answered Jun 07 '17 at 06:59

Evgeniy Kleban

6,794
13
54
107

score 1 · Answer 3 · answered Jun 07 '17 at 07:30

NSPredicate is nice, another way is using containsString: method like

//assumes all objects in the array are NSStrings
- (NSArray *)array:(NSArray *)array containsSubstring:(NSString *)substring {
    NSMutableArray *newArray = [[NSMutableArray alloc] init];
    for (NSString *string in array) {
        if([string containsString:substring]) {
            [newArray addObject:string];
        }
    }
    return newArray;
}

now you can call it like

NSArray *stringArray = @[@"P12300", @"P23400", @"P5430", @"P678"];
NSArray *subArray = [self array:stringArray containsSubstring:@"P23"];
NSLog(@"%@", subArray);

Swift 3:

in Swift it's super easy using filter

let array: [String] = ["P12300", "P23400", "P5430", "P678"]
let newArray = array.filter {
    $0.contains("P123")
}
print(newArray)

IOS : containsObject Check for String

3 Answers3