How to add objects to an NSArray using for loop?

Question

I want to add the [NSDecimalNumber numberWithInt:i] to an array using for loop.

It is hardcoded :

 NSArray *customTickLocations = [NSArray arrayWithObjects: [NSDecimalNumber numberWithInt:1],[NSDecimalNumber numberWithInt:2],[NSDecimalNumber numberWithInt:3],[NSDecimalNumber numberWithInt:4],[NSDecimalNumber numberWithInt:5],[NSDecimalNumber numberWithInt:6],[NSDecimalNumber numberWithInt:7],[NSDecimalNumber numberWithInt:8],[NSDecimalNumber numberWithInt:9],[NSDecimalNumber numberWithInt:10],[NSDecimalNumber numberWithInt:11],[NSDecimalNumber numberWithInt:12],nil];

I want like this, but I can add only one object here....

for (int i=0; i<totalImagesOnXaxis; i++)
{
    customTickLocations = [NSArray arrayWithObject:[NSDecimalNumber numberWithInt:i]];
}

Please help me out of this, Thanks in Advance, Madan

Why do you need the array anyway? Looks like the value in the array at index `i` is always `i`. — raymi, Oct 21 '11 at 08:53

EmptyStack · Answer 1 · 2013-05-24T05:00:22.157

46

NSArray is immutable. Use the mutable version, NSMutableArray.

edited May 24 '13 at 05:00

answered Oct 21 '11 at 07:24

EmptyStack

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score 22 · Answer 2 · answered Oct 21 '11 at 07:25

22

NSMutableArray * customTickLocations = [NSMutableArray new];
for (int idx = 0; idx < 12; ++idx) {
    [customTickLocations addObject:[NSDecimalNumber numberWithInt:idx]];
}

...

answered Oct 21 '11 at 07:25

justin

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score 10 · Answer 3 · answered May 24 '13 at 05:04

you cannot add Objects at run time to NSArray.For adding or removing objects at Run time you have to use NSMutableArray.

NSMutableArray *mutableArray=[[NSMutableArray alloc] init];
for (int i=0; i<10; i++) {
    [mutableArray addObject:[NSDecimalNumber numberWithInt:i]];
}

score 7 · Answer 4 · answered Oct 21 '11 at 07:25

NSMutableArray *customTickLocations = [NSMutableArray array];
for (int i=0; i<totalImagesOnXaxis; i++)
{
    [customTickLocations addObject:[NSDecimalNumber numberWithInt:i]];
}

The NSMutableArray class declares the programmatic interface to objects that manage a modifiable array of objects. This class adds insertion and deletion operations to the basic array-handling behavior inherited from NSArray

NSMutableArray Class Reference

score 5 · Answer 5 · answered May 29 '15 at 09:35

I found that using this technique is a great way to easily add a few more elements to an NSArray, this was the answer I was looking for when I came to this thread so am posting it as it is a great easy addition.

If I want to add a new array to my current array

currentArray = [currentArray arrayByAddingObjectsFromArray: newArray];

score 5 · Answer 6 · edited Feb 07 '20 at 12:51

5

NSMutableArray *customTickLocations = [[NSMutableArray alloc] init];

for(int i = 0; i<WhateverNoYouWant;i++)
{
  NSDecimalNumber * x = [NSDecimalNumber numberWithInt:i]
  [customTickLocations addObject:x]
}

edited Feb 07 '20 at 12:51

Bruno Bieri

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answered Oct 21 '11 at 07:25

Radu

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score 1 · Answer 7 · answered Sep 13 '16 at 08:52

1

NSArray add object like this:

NSArray *arr = @["1","2","3","4"];

I think NSArray can not addObject like NSMutableArray. You should try it:

NSMutableArray *mulArr = [NSMutableArray new];
[mulArr addObject:[NSDecimalNumber numberWithInt:number]];

answered Sep 13 '16 at 08:52

AmyNguyen

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How to add objects to an NSArray using for loop?

7 Answers7