How to check if an instance of NSMutableArray is null or not

问题

How to check an NSMutableArray is null or not ?

回答1:

If you want to check if it is empty:

if ([myMutableArray count] == 0) { ... }

If you want to check if the variable is nil:

if (!myMutableArray) { ... }

or:

if (myMutableArray == nil) { ... }

回答2:

//if the array has a count of elements greater than 0, then the array contains elements
if(myarray.count>0){
    NSlog(@"myarray contains values/elements");
}
else{ //else the array has no elements
    NSlog(@"myarray is nil");
}

回答3:

There are multiple ways to check it.

1. if (array == [NSNull null])
   {
       //myarray is blank
   }
   

2. if(array.count==0)
   {
       //myarray is blank
   }
   

3. if(array == nil)
   {
       //my array is blank
   }
   

回答4:

You can check this way also...

if self.yourMutableArray.count == 0 {
     // Your Mutable array is empty. 
} else {
    // Your Mutable array is not empty.
}

来源：https://stackoverflow.com/questions/2048048/how-to-check-if-an-instance-of-nsmutablearray-is-null-or-not