Loop Through NSArray And Check Objects in Objective-C - objective-c

Question

I'm trying to loop inside the objects of my array and would like to know how can I check the contents of the objects inside it and then do something when my search doesn't apply.
For example:
myArray = #[#"A1", #"A2", #"A3", #"B1", #"B2", #"B3", #"C1", #"C2", #"C3"];
I'd like to check the contents of myArray and if the object contains the letter A, I'll actually create a button until I create a row of buttons with objects of the letter A. If it contains a different letter, say B, I'll create a different row of buttons below the letter A row of buttons.
It will look like this:
[A1] [A2] [A3]
[B1] [B2] [B3]
[C1] [C2] [C3]
I'm thinking of doing a fast enumeration like this:
for (NSString *string in myArray)
{
if (// string has letter A)
{
Add string to array of A
}
else if (// string has letter B)
{
Add string to array of B
}
else if (// string has letter C)
{
Add string to array of C
}
}
But I'm not sure if I'm doing it right and fast.

Answer 1

This kind of approach might help indirectly. I'm not entirely sure what is being asked, so make of this what you will.
If you want to gather up by prefix, build an NSMutableDictionary whose keys will be #"A", #"B", ... and values are instances of NSMutableArray. For each string in your myArray, take it's prefix as the key to look up the array value in the dictionary, and add.
Something along the following lines:
NSArray *myArray = #[#"A1", #"A2", #"A3", #"B1", #"B2", #"B3", #"C1", #"C2", #"C3"];
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
for (NSString *s in myArray) {
if ([s length] < 1) {
continue;
}
NSString *key = [s substringToIndex:1];
if (![dict objectForKey:key]) {
[dict setObject:[NSMutableArray array] forKey:key];
}
NSMutableArray *bucket = [dict objectForKey:key];
[bucket addObject:s];
}
This kind of approach, which again may not directly answer your question, might prove instructive. It also has the advantage of being extensible - no need for yet another if clause.
Edit: The output of 'po dict' above in the console reads
(lldb) po dict
$2 = 0x0a33e660 {
A = (
A1,
A2,
A3
);
B = (
B1,
B2,
B3
);
C = (
C1,
C2,
C3
);
}

Answer 2

Find the character in string by using NSRange and do ur stuff. Like this
Try :
for (NSString *string in myArray)
{
if ([string rangeOfString:#"A"].location != NSNotFound)//Contains "A"
{
Add string to array of A
}
else if ([string rangeOfString:#"B"].location != NSNotFound)//Contains "B"
{
Add string to array of B
}
else if ([string rangeOfString:#"C"].location != NSNotFound)//Contains "C"
{
Add string to array of C
}
}
ope this helps u.