How to check array is empty in iPhone - ios

Question

I have one array of array.I want check my inner array is empty or not.and I am checking objects of array are empty string.
Here is my code :
NSMutableArray *newArray = [NSMutableArray array];
NSMutableArray *selectArray = [NSMutableArray array];
for (int i = 0; i < [newArray count]; i++)
{
NSArray *arr = [newArray objectAtIndex:i];
if ([arr count] > 0)
{
NSString *str = [arr objectAtIndex:0];
if (![str isEqualToString:#""])
{
[selectArray addObject:str];
}
}
}
my newArray is array of array.I want to add strings in selectArray which are not empty.but, only 0th index object is added in selectArray multiple times.
Please suggest me, where i am doing wrong.thanks

Answer 1

Thats because you are just getting the 0'th element of your newArray's elements, I mean this line
NSString *str = [arr objectAtIndex:0];
you should put another for in your code. Use this code instead of yours
NSMutableArray *newArray = [NSMutableArray array];
NSMutableArray *selectArray = [NSMutableArray array];
for (int i = 0; i < [newArray count]; i++){
NSArray *arr = [newArray objectAtIndex:i];
for (int j = 0; j < [arr count]; j++){
NSString *str = [arr objectAtIndex:j];
if (![str isEqualToString:#""]){
[selectArray addObject:str];
}
}
}

Answer 2

Use this code You not need to create any extra variable.
for (int i = 0; i < [newArray count]; i++)
{
for (int j = 0; j < [[newArray objectAtIndex:i] count]; j++)
{
if (![[[newArray objectAtIndex:i] objectAtIndex:j] isEqualToString:#""])
{
[selectArray addObject:str];
}
}
}

Answer 3

You can use following generic function to check any of the value or object is empty or null.
-(BOOL)isEmpty:(id)object{
return object == nil
|| [object isKindOfClass:[NSNull class]]
|| ([object respondsToSelector:#selector(length)]
&& [(NSData *)object length] == 0)
|| ([object respondsToSelector:#selector(count)]
&& [(NSArray *)object count] == 0);
}

Answer 4

You can try with this
NSMutableArray *newArray = [NSMutableArray array];
NSMutableArray *selectArray = [NSMutableArray array];
for (NSArray *arrayFromNewArray in newArray) {
if ([arrayFromNewArray count] > 0)
{
NSString *str = [arrayFromNewArray firstObject];
if (![str isEqualToString:#""])
{
[selectArray addObject:str];
}
}
}

Answer 5

You should be
NSMutableArray *newArray = [NSMutableArray array];
NSMutableArray *selectArray = [NSMutableArray array];
for (int i = 0; i < [newArray count]; i++)
{
NSArray *arr = [newArray objectAtIndex:i];
for (int j = 0; j < [arr count]; j++)
{
NSString *str = [arr objectAtIndex:j];
if (![str isEqualToString:#""])
{
[selectArray addObject:str];
}
}
}
Problem is you forgot the second loop :) Let me know if I am correct.