I am using swift String(format:...) and need to compute values in the format string itself using ternary operator, something like this but it doesn't compiles.
String(format: "Audio: \(numChannels>1?"Stereo": "Mono")")
In Objective-C, I could do like this:
[NSString stringWithFormat:#"Audio: %#", numChannels > 1 ? #"Stereo" : #"Mono"];
How do I achieve the same elegance in Swift without having an intermediate variable?
Due to the missing spaces around the operators in the conditional expression, the compiler misinterprets 1?"Stereo" as optional chaining. It should be
String(format: "Audio: \(numChannels>1 ? "Stereo" : "Mono")")
instead. However, since the format string has no placeholders at all, this is equivalent to
"Audio: \(numChannels > 1 ? "Stereo" : "Mono")"
One option is to use String(format:) with a placeholder and the conditional expression as the parameter for the placeholder
String(format: "Audio = %#", numChannels > 1 ? "Stereo" : "Mono")
I really unable to find any workaround for regular expression to input price in decimal.
This what I want:-
12345
12345.1
12345.12
12345.123
.123
0.123
I also want to restrict digits.
I really created one but not validating as assumed
^([0-9]{1,5}|([0-9]{1,5}\.([0-9]{1,3})))$
Also want to know how is above expression different from the one
^([0-9]{1,5}|([0-9].([0-9]{1,3})))$ thats working fine.
Anyone with good explanation.
"I am using NSRegularExpression - Objective C" if this helps to answer more precisely
- (IBAction)btnTapped {
NSRegularExpression * regex = [NSRegularExpression regularExpressionWithPattern:
#"^\\d{1,5}([.]\\d{1,3})?|[.]\\d{1,3}$" options:NSRegularExpressionCaseInsensitive error:&error];
if ([regex numberOfMatchesInString:txtInput.text options:0 range:NSMakeRange(0, [txtInput.text length])])
NSLog(#"Matched : %#",txtInput.text);
else
NSLog(#"Not Matched : %#",txtInput.text);
}
"I am doing it in a buttonTap method".
This simple one should suit your needs:
\d*[.]?\d+
"Digits (\d+) that can be preceded by a dot ([.]?), which can itself be preceded by digits (\d*)."
Since you're talking about prices, neither scientific notation nor negative numbers are necessary.
Just as a point of interest, here's the one I usually used, scientific notation and negative numbers included:
[-+]?\d*[.]?\d+(?:[eE][-+]?\d+)?
For the new requirements (cf. comments), you can't specify how many digits you want on the first regex I gave, since it's not the way it has been built.
This one should suit your needs better:
\d{1,5}([.]\d{1,3})?|[.]\d{1,3}
"Max 5 digits (\d{1,5}) possibly followed ((...)?) by a dot itself followed by max 3 digits ([.]\d{1,3}), or (|) simply a dot followed by max 3 digits ([.]\d{1,3})".
Let's do this per-partes:
Sign in the beginning: [+-]?
Fraction number: \.\d+
Possible combinations (after sign):
Number: \d+
Fraction without zero \.\d+
And number with fraction: \d+\.\d+
So to join it all together <sign>(number|fraction without zero|number with fraction):
^[+-]?(\d+|\.\d+|\d+\.\d+)$
If you're not restricting the lengths to 5 digits before the decimal and 3 digits after then you could use this:
^[+-]?(?:[0-9]*\.[0-9]|[0-9]+)$
If you are restricting it to 5 before and 3 after max then you'd need something like this:
^[+-]?(?:[0-9]{0,5}\.[0-9]{1,3}|[0-9]{1,5})$
As far as the difference between your regexes goes, the first one limits the length of the number of digits before the decimal marker to 1-5 with and without decimals present. The second one only allows a single digit in front of the decimal pointer and 1-5 digits if there is no decimal.
How about this: ^([+-])?(\d+)?([.,])?(\d+)?$
string input = "bla";
if (!string.IsNullOrWhiteSpace(input))
{
string pattern = #"^(\s+)?([-])?(\s+)?(\d+)?([,.])?(\d+)(\s+)?$";
input = input.Replace("\'", ""); // Remove thousand's separator
System.Text.RegularExpressions.Regex.IsMatch(input, pattern);
// if server culture = de then reverse the below replace
input = input.Replace(',', '.');
}
Edit:
Oh oh - just realized that's where we run into a little bit of a problem if an en-us user uses ',' as thousand's separator....
So here a better one:
string input = "+123,456";
if (!string.IsNullOrWhiteSpace(input))
{
string pattern = #"^(\s+)?([+-])?(\s+)?(\d+)?([.,])?(\d+)(\s+)?$";
input = input.Replace(',', '.'); // Ensure no en-us thousand's separator
input = input.Replace("\'", ""); // Remove thousand's separator
input = System.Text.RegularExpressions.Regex.Replace(input, #"\s", ""); // Remove whitespaces
bool foo = System.Text.RegularExpressions.Regex.IsMatch(input, pattern);
if (foo)
{
bool de = false;
if (de) // if server-culture = de
input = input.Replace('.', ',');
double d = 0;
bool bar = double.TryParse(input, out d);
System.Diagnostics.Debug.Assert(foo == bar);
Console.WriteLine(foo);
Console.WriteLine(input);
}
else
throw new ArgumentException("input");
}
else
throw new NullReferenceException("input");
Edit2:
Instead of going through the hassle of getting the server culture, just use the tryparse overload with the culture and don't resubstitute the decimal separator.
double.TryParse(input
, System.Globalization.NumberStyles.Any
, new System.Globalization.CultureInfo("en-US")
, out d
);
NSString* abc = #"\u003ca\\tb\\tc\u003e";
How can I convert it to <a b c>
For horizontal tab, you should use "\t". And for "<" or ">" unicode character pass its hexadecimal value and log it by character specifier (%c) as i used below. It must work for you as I have tried in my xcode and it worked for me.
NSString * requiredStrg = [NSString stringWithFormat:#"%c a\tb\tc %c",0x3c,0x3e];
NSLog(#"%#",requiredStrg);
I'm use RegexKitLite to match some texts:
xxx*[abc]*xxx
and I want to match [abc],and use this regular:
NSString *result = [#"xxx[abc]xxx" stringByMatching:#"\\[(.*)?\\]" capture:1];
then, the result is [abc].But, if have linebreak in there:
xxx[ab
c]xxx
It's dosen't work.
I use ([\s\S]*), also dosen't math [abc].
How can I match this text?
thank you
The . does not match new lines by default. You could use
... stringByMatching:#"(?s:\\[(.*)?\\])" ...
// ^^^^ ^
or supply the RKLDotAll option with the -stringByMatching:options:inRange:capture:error: method.
Alternatively, you could use the greedy variant
#"\\[([^\\]]*)\\]" // \[ ( [ ^\] ] ) \]
I was wondering if anyone might know what the regular expression would be to turn this:
West4thStreet
into this:
West 4th Street
I'm going to add the spaces to the string in Objective-C.
Thanks!
I don't know exactly where you want to put in spaces, but try something like [a-z.-][^a-z .-] and then put a space between the two characters in each match.
Something like this perl regex substitution would put a space before each group of capital letters or numbers. (You'd want to trim space before the string in this case also.) I assume you don't want it to break up eg: 45thStreet to 4 5th Street
Letters I'm less certain of.
s/([A-Z]+|[0-9]+)/ \1/g
I created a pattern to not match the beginning of the line for my personal amusement:
s/([^\^])([A-Z]+|[0-9]+)/\1 \2/g
This should work, if all your strings truly match the format of your example:
([A-Z][a-z]+)(\d+[a-z]+)([A-Z][a-z]+)
You can then separate the groups with spaces.
Another option would be to not use RegExKit and use code to loop through each character in the string and insert a space after each capital letter or after first decimal..
NSMutableString *myText2 = [[NSMutableString alloc] initWithString:#"The1stTest"];
bool isNumber=false;
for(int x=myText2.length-1;x>1;x--)
{
bool isUpperCase = [[NSCharacterSet uppercaseLetterCharacterSet] characterIsMember:[myText2 characterAtIndex:x]];
bool isLowerCase = [[NSCharacterSet lowercaseLetterCharacterSet] characterIsMember:[myText2 characterAtIndex:x]];
if([[NSCharacterSet decimalDigitCharacterSet] characterIsMember:[myText2 characterAtIndex:x]])
isNumber = true;
if((isUpperCase || isLowerCase) && isNumber)
{
[myText2 insertString:#" " atIndex:x+1];
isNumber=false;
}
if(isUpperCase)
[myText2 insertString:#" " atIndex:x];
}
NSLog(#"%#",myText2); // Output: "The 1st Test"