Even Odd in Objective-C

Even Odd in

Objective-C

Welcome to the Even Odd in Objective-C page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

#import <Foundation/Foundation.h>

@interface NSString (Parsing)
@property(nonatomic, readonly, nullable) NSNumber* strictIntegerNumber;
@end

@implementation NSString (Parsing)

- (NSNumber*)strictIntegerNumber {
    NSString* trimmed = [self
        stringByTrimmingCharactersInSet:NSCharacterSet
                                            .whitespaceAndNewlineCharacterSet];
    if (trimmed.length == 0) return nil;

    NSInteger offset = 0;
    if ([trimmed hasPrefix:@"-"] || [trimmed hasPrefix:@"+"]) {
        offset = 1;
    }

    if (trimmed.length <= offset) return nil;

    NSString* core = [trimmed substringFromIndex:offset];
    NSRange invalidRange =
        [core rangeOfCharacterFromSet:NSCharacterSet.decimalDigitCharacterSet
                                          .invertedSet];

    if (invalidRange.location != NSNotFound) {
        return nil;
    }

    return @(trimmed.longLongValue);
}

@end

int main(int argc, const char* argv[]) {
    @autoreleasepool {
        if (argc < 2) {
            puts("Usage: please input a number");
            return 1;
        }

        NSNumber* number = @(argv[1]).strictIntegerNumber;

        if (!number) {
            puts("Usage: please input a number");
            return 1;
        }

        puts(number.longLongValue % 2 == 0 ? "Even" : "Odd");
    }
    return 0;
}

Even Odd in Objective-C was written by:

• rzuckerm
• Siddhant
• Ștefan-Iulian Alecu

If you see anything you'd like to change or update, please consider contributing.

How to Implement the Solution

No 'How to Implement the Solution' section available. Please consider contributing.

How to Run the Solution

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