if else statements confusion Objective-C [closed] - iphone

Question

Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
Questions asking for code must demonstrate a minimal understanding of the problem being solved. Include attempted solutions, why they didn't work, and the expected results. See also: Stack Overflow question checklist
Closed 9 years ago.
Improve this question
In Xcode, I have an if and an else statement.
I would like to make the statement have multiple conditions, but only one of them have to be 'YES'.
For example:
I have a NSString, the value of that string is:
[NSstring stringWithFormat:#"ABCDEFG12345"];
I need to have my if statement check for if A or 1 or 5 is in the string. I understand how to use [string rangeOfString:#"CheckHere"];.
I need my if statement to find one or all of those given letters/numbers. If one is found, execute the given code, if two are found, execute the given code, if all three are found, execute the given code.

Answer 1

You need no if-else. You can do something like this.
NSString* string = #"ABCDEFG12345";
int foundA = [string rangeOfString:#"A"].location == NSNotFound ? 0 : 1;
int found1 = [string rangeOfString:#"1"].location == NSNotFound ? 0 : 1;
int found5 = [string rangeOfString:#"5"].location == NSNotFound ? 0 : 1;
int foundCount = foundA + found1 + found5;
switch(foundCount) {
case 1: [self executeOne]; break;
case 2: [self executeTwo]; break;
case 3: [self executeThree]; break;
}

Answer 2

One possible approach:
Let's assume you can piece together the (actually somewhat tedious) use of rangeOfString and rangeOfCharacter calls together and can write a method like this:
-(NSInteger)numberOfMatchesFoundInString:(NSString*)inputString;
which lets you pass in a string, and returns a 0,1,2... based on how many matches are found.
To use this convenient result in a highly readable way, you can use a switch statement.
NSInteger* matches = [self numberOfMatchesFoundInString:someString];
switch (matches) {
case 0:
//execute some code here for when no matches are found
break;
case 1:
//execute some different code when one match is found
break;
case 2:
//you get the idea
break;
default:
//some code to handle exceptions if the numberOfMatchesFoundInString method went horribly wrong
break;
Of course some people will tell you that this is functionally no different than calling
if (someCondition) {
//do some stuff
}
else if (someOtherCondition) {
//do some different stuff
}
etc...
but really, you can make either one work.

Answer 3

There are a few useful techniques you can use for string comparisons.
If you just need test if your string is one of a list of strings, use something like this:
NSArray *options = #[#"first", #"second", #"third"];
if ([options contains:inputString]) {
// TODO: Write true block
} else {
// TODO: Write else block
}
If you want to check if your string contains at least one character from a set, use NSString -rangeOfCharacterFromSet:.
Unfortunately, if you want to check if your string contains one or more strings, you have no choice but to write it out the long way. If you do it frequently enough, you may choose to write a class category.
- (BOOL)containsAtLeastOneSubstring:(NSArray *)substrings
{
for (NSString *aString in substrings) {
NSRange range = [self rangeOfString:aString];
if (range.location!=NSNotFound) {
return YES;
}
}
return NO;
}
-