如何从Objective-C中的文本文件解析坐标？

Question

I have a text file named coordinates.txt with some coordinates in it(surprisingly). The format looks like this:

20.580070,47.775910, 
20.582950,47.776640, 
20.585660,47.777460, 
20.587280,47.777960, 
20.588280,47.778300, 
20.621870,47.789710,

I want to parse through the file, and add the first coordinate to an int variable named latitude and the second one to an int variable named longitude. Than print out the two variables to the console and do this for every line separately.I know I should use a loop but I am not exactly sure how so can you guys please help me out!

EDIT:

Here is my code so far:

        NSString *latitude = @"0";
        NSString *longitude = @"0";
        NSString* filePath = @"/Users/Balazs/coordinates.txt";



        NSString *entireFileInString = [NSString stringWithContentsOfFile:filePath];
        NSArray *lines = [entireFileInString componentsSeparatedByString:@","];
        for (NSString *line in lines) {
                latitude = line;
        }
        NSLog([NSString stringWithFormat:@"%@",latitude]);

I know how to read the whole text into the latitude variable but not just the first part and not line by line. Also the text which is read is stored as a string so I am not sure how to convert those into doubles..

PS: Sorry for the noob question!!:/

Answer 1

Assuming the text file's in your bundle, you can store the text in an NSString like so:

NSString* path = [[NSBundle mainBundle] pathForResource:@"coordinates" 
                                                 ofType:@"txt"];

NSString* content = [NSString stringWithContentsOfFile:path
                                              encoding:NSUTF8StringEncoding
                                                 error:NULL];

Then separate the text into lines using componentsSeparatedByString: , go through each line with a loop, then separate each line again using componentsSeparatedByString: into its longitude and latitude values before printing. For example:

NSArray *lines = [content componentsSeparatedByString:@"\n"];
for (NSString *line in lines) {
    NSArray *values = [line componentsSeparatedByString:@","];
    double latitude = [[values objectAtIndex:0] doubleValue];
    double longitude = [[values objectAtIndex:1] doubleValue];
    NSLog(@"%f, %f", latitude, longitude);
}