I'm trying to generate integer array using for loop. Here is my code:
int total = 20;
for(int x = 0; x < total; x++)
{
NSArray arr = [NSArray arrayWithObjects: [NSNumber numberWithInt:total]];
}
With the above implementation I get only one object in array, the last one. What to do so arr to contain the numbers from 1 to 20 ?
int total = 20;
NSMutableArray *arr = [[NSMutableArray alloc] init];
for(int x = 0; x < total; x++)
{
[arr addObject:[NSNumber numberWithInt:x]];
}
// release the array when you are done with it.
[[NSMutableArray alloc] init]; instead of [NSMutableArray alloc] init]. Cheers
You should initialize your array outside of the loop rather than inside the loop.
Change your code to this:
int total = 20;
NSMutableArray *arr = [NSMutableArray array];
for(int x = 0; x < total; x++)
[arr addObject:[NSNumber numberWithInt:x]];
You're recreating the array every time. Make the NSArray an iVar or initialize it outside of the loop.
NSArray is an immutable class (it means you cannot add/remove objects runtime) and what you are doing here is quite strange. You create a new array inside the loop.
You could use a NSMutableArray but externally to the loop. In this manner you have a reference outside the loop and you can add objects to it. NSMutableArray is mutable. You can change objects runtime.
NSMutableArray* numberArray = [[NSMutableArray alloc] init];
for(int x = 0; x < total; x++)
{
[numberArray addObject:[NSSnumber numberWithInt:x]];
}
NSMutableArray *arr = [NSMutablearray arrayWithCapacity:total];
for(int x = 0; x < total; x++)
{
[arr addObject:[NSNumber numberWithInt:x]];
}
At every loop you created new array with one object. in this example you create array once and than just add objects to it.
[NSNumber numberWithInt: i] was originally meant, but YMMV.
Every time you are creating a new NSArray and assigning it to NSArray *arr. +arrayWithObjects: method create a new array. NSArray is not mutable , you should use NSMutableArray.
NSArray creates static arrays, and NSMutableArray creates dynamic arrays.
NSMuatbleArray *arr = [[NSMutableArray alloc]init];
for(int i =0 ; i<20 ; ++i)
{
[array addObject:[NSNumber numberWithInt:i]];
}
