Question

sorry but i’m still struggling to make this code working. It works if with a 2 digits number but it crashes with a single digit number. How can I verify if the NSString *secDigit has a value or is null. I hope my question is clear. Thanks in advance.

NSString *depositOverTotalRwy = [NSString stringWithFormat:@"%@", [deposit text]];
NSArray *components = [depositOverTotalRwy
                       componentsSeparatedByString:@"/"];
NSString *firstThird = [components objectAtIndex:0];

    char firstChar = [firstThird characterAtIndex:0];
    char secChar = [firstThird characterAtIndex:1];
    NSString *firstDigit = [NSString stringWithFormat:@"%c",firstChar];
NSString *secDigit = [NSString stringWithFormat:@"%c", secChar];

    NSLog(@" i'm %@", firstDigit);
    NSLog(@" i'm %@", secDigit);

if ([firstDigit  isEqualToString: @"1"]) {
    firstDigit=@"wet";
    NSLog(@"wet");
}
if ([firstDigit  isEqualToString: @"2"]) {
    firstDigit=@"wet";
    NSLog(@"snow");

}
if ([firstDigit  isEqualToString: @"3"]) {
    firstDigit=@"wet";
    NSLog(@"ice");
    }

if ([secDigit  isEqualToString: @"1"]) {
    secDigit=@"wet";
    NSLog(@"wet");
}
if ([secDigit  isEqualToString: @"2"]) {
    secDigit=@"snow";

    NSLog(@"snow");
}
if ([secDigit  isEqualToString: @"3"]) {
    secDigit=@"ice";
    NSLog(@"ice");
}

thanks to all of you….. here my code (working now):

   NSString *depositOverTotalRwy = [NSString stringWithFormat:@"%@", [deposit text]];
NSArray *components = [depositOverTotalRwy
                       componentsSeparatedByString:@"/"];
NSString *firstThird = [components objectAtIndex:0];

    char firstChar = [firstThird characterAtIndex:0];
    NSString *firstDigit = [NSString stringWithFormat:@"%c",firstChar];

    NSLog(@" i'm %@", firstDigit);

if ([firstDigit  isEqualToString: @"1"]) {
    firstDigit=@"wet";
    NSLog(@"wet");
}
if ([firstDigit  isEqualToString: @"2"]) {
    firstDigit=@"wet";
    NSLog(@"snow");

}
if ([firstDigit  isEqualToString: @"3"]) {
    firstDigit=@"wet";
    NSLog(@"ice");
    }
if ([firstThird length] >1) {
    char secChar = [firstThird characterAtIndex:1];
    NSString *secDigit = [NSString stringWithFormat:@"%c", secChar];


if ([secDigit  isEqualToString: @"1"]) {
    secDigit=@"wet";
    NSLog(@"wet");
}
if ([secDigit  isEqualToString: @"2"]) {
    secDigit=@"snow";

    NSLog(@"snow");
}
if ([secDigit  isEqualToString: @"3"]) {
    secDigit=@"ice";
    NSLog(@"ice");
}
}

Answer 1

I guess you code crashes in this line:

char secChar = [firstThird characterAtIndex:1];

This is because you try to access a character outside of the string bounds. You need to guard against this by checking the length of the string first:

if ([firstThird count] > 1) {
    // String has 2 or more characters, do all the stuff that involves
    // a second character.
    char secChar = [firstThird characterAtIndex:1];
    NSString *secDigit = [NSString stringWithFormat:@"%c", secChar];

    if ([secDigit  isEqualToString: @"1"]) {
        secDigit=@"wet";
        NSLog(@"wet");
    }
}

But I’d also like to recommend to not use an NSString here, as you already have a char. Just do something like this:

if ([firstThird count] > 1) {
    // String has 2 or more characters, do all the stuff that involves
    // a second character.
    char secChar = [firstThird characterAtIndex:1];

    if (secChar == '1') {
        secDigit=@"wet";
        NSLog(@"wet");
    }
}