convert NSArray in float[]

        NSArray *c=[NSArray arrayWithObjects:@"1",@"8",@"4",@"2",nil];

        

        NSEnumerator *enumerator;

        float * cArray;

        id obj;

        int index=0;

        

        cArray = (float *) malloc(sizeof(float) * [c count]);

        enumerator = [c objectEnumerator];

        while(obj = [enumerator nextObject])

        {

            cArray[index] = [obj floatValue];

            index++;

        }

        

       

How to sort an NSArray with integers elements ?

 Its very very simple.

NSMutableArray *heightArray=[[NSMutableArray alloc]init];
for(int i=0; i<10; i++)
{
     float value=(rand()%100.0)/10;
     [heightArray addObject:[NSNumber numberWithFloat:value]];
}
NSArray *sortedArray = [heightArray sortedArrayUsingSelector:@selector(compare:)];

//Lets print the sorted Array

NSLog(@"sortedArray=%@",sortedArray);

For sorting an array which contains  instance of custom class. You can check this old post.

Copy items of NSMutableArray into another ?

Lets say you have arrayA and arrayB, arrayB could be NSArray or NSMutableArray.
But arrayA should be mutable.

  [arrayA addObjectsFromArray:arrayB];

Here you are copying items from  arrayB to arrayA. Make sure you have already alloc memory for arrayA as:

arrayA = [[NSMutableArray alloc]init];

Case 2: If you want to create a copy an array to NSArray, you can do so as following:

NSArray *db=[[NSArray alloc]initWithArray:availListArray];