Question

I have a textview that already has text extracted from a website. So, let’s say the text in the text view has this text:

Save Location 

84°F 

Clear 

Feels like 90°F

In this text, how can I extract the text that says 84 in the “84°F” to a string? Remember that the 84 is a constantly changing variable from the website so sometimes it’ll be a different number and I can’t search for the number directly. If you know how to do this please let me know 🙂 Thanks for your time.

Answer 1

Try something like this:

NSString *originalString = @"Save Location 84°F Clear Feels like 90°F";

NSMutableString *stringWithNums = [NSMutableString stringWithCapacity:originalString.length];

NSScanner *scanner = [NSScanner scannerWithString:originalString];
NSCharacterSet *numbers = [NSCharacterSet 
                       characterSetWithCharactersInString:@"0123456789"];

while ([scanner isAtEnd] == NO) {
    NSString *buffer;
    if ([scanner scanCharactersFromSet:numbers intoString:&buffer]) {
        [stringWithNums appendString:buffer];

    } else {
        [scanner setScanLocation:([scanner scanLocation] + 1)];
        [stringWithNums appendString:@" "];
    }
}

Now stringWithNums will contains something like this:

84 (some spaces) 90

Then you could parse stringWithNums like this:

NSArray *tempArray = [stringWithNums componentsSeparatedByString: @" "];
NSString *finalTemperature;

for(int index = 0; index < [tempArray count]; index++){

    if([[tempArray objectAtIndex:index] intValue] != 0 && [[tempArray objectAtIndex:index] intValue] < 200){
        finalTemperature = [tempArray objectAtIndex: index];
        break;
    }
}

finalTemperature will contain “84”. You could put this in method form and pass in originalString as an argument so you could reuse this code. Hope this helps and if you have any questions, make sure to ask in the comments!

UPDATE:
I added this line:
&& [[tempArray objectAtIndex:index] intValue] < 200

to the if statement above, so it now looks like this:

if([[tempArray objectAtIndex:index] intValue] != 0 && [[tempArray objectAtIndex:index] intValue] < 200){

In the website text, it looks like the only number before the “82” is a zip code, which is 5 digits long. In reality, all temperatures (on Earth) are below 200 (3 digits), so the extra line I put in makes sure that the final temperature is a three or less digit number and not a 5 digit zip code.

Hope this helps!