I am trying to split a string that is a complex number into real and imaginary number.
I tried to find the solution on the internet, but all of the solutions that I found remove the splitting character.
I will show on example what exactly I want to do:
I have a string that is in this form : -3.5+6.7i
I want to split the string into -3.5 and +6.7i
Thanks for the help!!!
This is quite easy:
NSString *complexNumber = @"-3.5+6.7i";
NSArray *components = [complexNumber componentsSeparatedByString:@"+"];
NSString *realPart = components[0];
NSString *imaginaryPart = [@"+" stringByAppendingString:components[1]];
Next question: how are you going to split @"-3.5-6.7i"?
NSRegularExpression if you want. Another option is just iterating over the characters of the string.Try this function. Haven't tested it, so it may need some tweaking
+ (NSMutableArray*)split:(NSString*)string on:(NSArray*)separators
{
NSMutableArray* answer = [[NSMutableArray alloc] init];
NSString* substring = [NSString stringWithString:string];
//slowly shrink the string by taking off strings from the front
while ([substring length] > 0)
{
int first = 0;
//look for the separator that occurs earliest and use that for what you are
//splitting on. There is a slight catch here. If you have separators "abc" and "bc",
//and are looking at string "xabcd", then you will find the strings "x", "a", and
//"bcd" since the separators share common substrings, meaning that the strings
//returned from this function are not guaranteed to start with one of the
//separators.
for (int j = 0; j < [separators count]; j++)
{
//need to start from index 1 so that the substring found before that caused
//the split is not found again at index 0
NSString* toCheck = [substring substringFromIndex:1];
int start = [substring rangeOfString:[separators objectAtIndex:j]].location;
if (start < first)
{
first = start;
}
}
[answer addObject:[substring substringToIndex:start]];
substring = [substring substringFromIndex:start];
}
return answer;
}
The accepted answer is terrible, it doesn't handle any of the obvious corner cases. Try this:
NSString * input = @"-3.5+6.7i";
NSString * const floatRe = @"\\d*(?:\\.\\d*)?";
NSString * const reStr = [NSString stringWithFormat:@"([-+]?%@)([-+]%@)i", floatRe, floatRe];
NSRegularExpression * re = [NSRegularExpression regularExpressionWithPattern:reStr options:(NSRegularExpressionOptions)0 error:NULL];
NSArray * matches = [re matchesInString:input options:(NSMatchingOptions)0 range:NSMakeRange(0, input.length)];
if (matches.count != 1) {
// Fail.
}
NSTextCheckingResult * match = matches[0];
double real = [[input substringWithRange:[match rangeAtIndex:1]] doubleValue];
double imag = [[input substringWithRange:[match rangeAtIndex:2]] doubleValue];
NSLog(@"%lf / %lf", real, imag);
NSRegularExpressionandNSScannerare the primary framework-provided ways to parsing/breaking up strings.