How to read an array of integer?

Question

NSMutableArray *Number=[NSArray arrayWithObjects: @"1", @"2", @"3", @"4", @"5", @"6", nil];

I have an array of interger and need to read them one by one. Can anyone please tell me how to code it?

Answer 1

Actually, you have an array of NSStrings.

Note also that assigning an NSArray instance to an NSMutableArray* reference doesn't make much sense.

In any case, you could:

for(NSString *foo in numberArray) {
    int i = [foo intValue];
    ....
}

Note that you should name variables starting with a lower case letter. Prevents confusion and conflicts with class names (what if you wanted to create a class named Number later?).

Answer 2

As an aside you should use:

NSMutableArray *numStrings=[NSMutableArray arrayWithObjects: @"1", @"2", @"3", @"4", @"5", @"6", nil];

The complier will let you assign a NSArray to an NSMutableArray but if you try to send it NSMutableArray specific messages, it may crash.

Answer 3

This is how you enumerate array, NSArray is immutable, of integers:

NSArray * numbers = [NSArray arrayWithObjects:[NSNumber numberWithInt:1],
                                              [NSNumber numberWithInt:2],
                                              [NSNumber numberWithInt:4],
                                              [NSNumber numberWithInt:5],
                                              [NSNumber numberWithInt:6],
                                              [NSNumber numberWithInt:7],
                                              nil];
// now print out
id obj;
NSEnumerator * enumerator;

enumerator = [numbers objectEnumerator];
while ((obj = [enumerator nextObject])) NSLog(@"%@", obj);

This is how you add integers dynamically to an array, NSMutableArray, (and then print the array):

NSLog(@"\ndynamically add integers:");

NSMutableArray * num2 = [[NSMutableArray alloc] init];
int i;
for ( i = 0; i < 10; ++i) [num2 addObject:[NSNumber numberWithInt:i]];

// now print out
enumerator = [num2 objectEnumerator];
while ((obj = [enumerator nextObject])) NSLog(@"%@", obj);

Output from both:

2010-01-27 14:51:40.307 x[5566] 1
2010-01-27 14:51:40.308 x[5566] 2
2010-01-27 14:51:40.308 x[5566] 4
2010-01-27 14:51:40.308 x[5566] 5
2010-01-27 14:51:40.308 x[5566] 6
2010-01-27 14:51:40.308 x[5566] 7
2010-01-27 14:51:40.308 x[5566]
dynamically add integers:
2010-01-27 14:51:40.308 x[5566] 0
2010-01-27 14:51:40.308 x[5566] 1
2010-01-27 14:51:40.308 x[5566] 2
2010-01-27 14:51:40.308 x[5566] 3
2010-01-27 14:51:40.308 x[5566] 4
2010-01-27 14:51:40.308 x[5566] 5
2010-01-27 14:51:40.308 x[5566] 6
2010-01-27 14:51:40.308 x[5566] 7
2010-01-27 14:51:40.308 x[5566] 8
2010-01-27 14:51:40.309 x[5566] 9