NestedToFlatArray

NestedToFlatTests.m

//
//  NestedToFlatTests.m
//  NestedToFlatTests
//
//  Created by Ishkhan Gevorgyan on 12/3/17.
//  Copyright © 2017 Ishkhan Gevorgyan. All rights reserved.
//

#import <XCTest/XCTest.h>
#import "NSMutableArray+FlatArray.h"

@interface NestedToFlatTests : XCTestCase


@end

@implementation NestedToFlatTests

- (void)setUp {
    [super setUp];
    // Put setup code here. This method is called before the invocation of each test method in the class.
}

- (void)tearDown {
    // Put teardown code here. This method is called after the invocation of each test method in the class.
    [super tearDown];
}

- (void)testExample {
    // This is an example of a functional test case.
    // Use XCTAssert and related functions to verify your tests produce the correct results.
}

- (void)testPerformanceExample {
    // This is an example of a performance test case.
    [self measureBlock:^{
        // Put the code you want to measure the time of here.
    }];
}

- (void)testForNilArray {

    NSMutableArray *nestedArray = nil;
    NSMutableArray *flatArray = nil;
    
    XCTAssertEqualObjects(flatArray, [nestedArray makeFlatArrayForNumbers], @"Nil case failed to flat");
}
- (void)testForEmptyArray {
    
     NSMutableArray * nestedArray = [NSMutableArray new];
     NSMutableArray * flatArray = [NSMutableArray new];
    
    XCTAssertEqualObjects(flatArray, [nestedArray makeFlatArrayForNumbers], @"Empty array failed to flat");
}

- (void)testArray {
    
    NSMutableArray * nestedArray = [NSMutableArray new];
    NSArray *array1 = @[@1,
                         @2,
                         @[@3, @4],
                         @[@5],
                         @[@[@6, @7], @8, @[@9, @[@10], @[]], @[]],
                         @[],
                         @11,
                         @[],
                         @[@11,@12,@13,@14,@15,@16,@17,@18,@19],
                         ];
    nestedArray = [NSMutableArray arrayWithArray:array1];

    NSMutableArray * flatArray = [NSMutableArray new];
    NSArray *array2 = @[@1, @2, @3, @4, @5, @6, @7, @8, @9, @10, @11,@11,@12,@13,@14,@15,@16,@17,@18,@19];
    flatArray = [NSMutableArray arrayWithArray:array2];
   
    XCTAssertEqualObjects(flatArray, [nestedArray makeFlatArrayForNumbers], @"Array failed to flat");
}

@end

NSMutableArray+FlatArray.h

//
//  NSMutableArray+FlatArray.h
//  NestedToFlat
//
//  Created by Ishkhan Gevorgyan on 12/3/17.
//  Copyright © 2017 Ishkhan Gevorgyan. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface NSMutableArray (FlatArray)

- (NSMutableArray *)makeFlatArrayForNumbers;

@end

NSMutableArray+FlatArray.m

//
//  NSMutableArray+FlatArray.m
//  NestedToFlat
//
//  Created by Ishkhan Gevorgyan on 12/3/17.
//  Copyright © 2017 Ishkhan Gevorgyan. All rights reserved.
//

#import "NSMutableArray+FlatArray.h"

@implementation NSMutableArray (FlatArray)

-(NSMutableArray *)makeFlatArrayForNumbers  // name is in such type to help to use only with Arrays with  Numbers
{
    NSMutableArray * flatArray = [NSMutableArray new];
    
    //Call to return flat the array
    [self makeFlatArrayFrom:self andWriteToArray:flatArray];
    return flatArray;
}
//recursive function of flatting Array
-(void)makeFlatArrayFrom:(NSMutableArray *)originalArray andWriteToArray:(NSMutableArray *)resultArray
{
    
    for(id element in originalArray)
    {
        if([element isKindOfClass:[NSNumber class]])
        {
            // add element to flat if number
            [resultArray addObject:element];
        }
        else
            if ([element isKindOfClass:[NSArray class]] || [element isKindOfClass:[NSMutableArray class]])
            {
               // recursive call if element is array typed
                [self makeFlatArrayFrom:element andWriteToArray:resultArray];
            }
            else
            {
               // exeption for using other typed elements
                NSLog(@"Object is not of NSNumber or NSArray type: %@", element);
                NSException* myException = [NSException
                                            exceptionWithName:@"ObjectNotNumberOrArray"
                                            reason:@"Object is not of NSNumber or NSArray type"
                                            userInfo:nil];
                @throw myException;
            }
    }
}


@end

ViewController.h

//
//  ViewController.h
//  NestedToFlat
//
//  Created by Ishkhan Gevorgyan on 12/3/17.
//  Copyright © 2017 Ishkhan Gevorgyan. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController

@end

ViewController.m

//
//  ViewController.m
//  NestedToFlat
//
//  Created by Ishkhan Gevorgyan on 12/3/17.
//  Copyright © 2017 Ishkhan Gevorgyan. All rights reserved.
//

#import "ViewController.h"
#import "NSMutableArray+FlatArray.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    [self testFlatten];
}

-(void)testFlatten
{
    //For testing we create the nested Array [[1,2,[3]],4]
    NSMutableArray * nestedArray = [NSMutableArray new];
    NSMutableArray * nest2 = [NSMutableArray new];
    [nest2 addObject:@3];
    NSMutableArray * nest1 = [NSMutableArray new];
    [nest1 addObject:@1];
    [nest1 addObject:@2];
    [nest1 addObject:nest2];
    [nestedArray addObject:nest1];
    [nestedArray addObject:@4];
    
    NSMutableArray * flattenArray = [NSMutableArray new];
    
    //Call to flat the array [[1,2,[3]],4] -> [1,2,3,4]
    flattenArray = [nestedArray makeFlatArrayForNumbers]; // usage
    
    NSLog(@"nested Array is%@",nestedArray);
    NSLog(@"flat Array is%@",flattenArray);
    
}

@end