I have a webpage that outputs an integer that I need to parse. I know how to get a string from a website in an UIWebView, but I need to get it as an integer. Converting a string to an integer using [myString integerValue] won't work here. How can I do this?
Edit: Here is my error
The reason behind the warning is that your variable is not an integer, but a pointer to an integer.
NSInteger *test = [onlineUsers integerValue];
^
Get rid of the asterisk
Related
hey just a couple quick noob questions about writing my first ios app. Ive been searching through the questions here but they all seem to address questions more advanced than mine so im getting confused.
(1) All I want to do is turn a string into an array of integers representing the ASCII code. In other words, I want to convert:
"This is some string. It has spaces, punctuation, AND capitals."
into an array with 62 integers.
(2) How do I get back from the NSArray to a string?
(3) Also, are these expensive operations in terms of memory or computation time? It seems like it might be if we have to create a new variable at every iteration or something.
I know how to declare all the variables and im assuming I run a loop through the length of the string and at each iteration I somehow get the character and convert it into a number with some call to a built in command.
Thanks for any help you can offer or links to posts that might help!
if you want to store the ascii values in an nsarray it is going to be expensive. NSArray can only hold objects so you're going to have to create an NSNumber for each ASCII value:
unsigned len = [string length];
NSMutableArray arr = [NSMutableArray arrayWithCapacity:len];
for (unsigned i = 0; i < len; ++i) {
[arr addObject:[NSNumber numberWithUnsignedShort:[string characterAtIndex:i]]];
}
2) to go back to an NSString you'll need to use an MSMutableString and append each byte to the NSMutableString.
After saying that I'd suggest you don't use this method if you can avoid it.
A better approach would be to use #EmilioPelaez's answer. To go back from a memory buffer to an NSString is simple and inexpensive compared to iterating and concatting strings.
NSString * stringFromMemory = [[NSString alloc] initWithBytes:buffer length:len encoding: NSASCIIStringEncoding];
I ended up using the syntax I found here. Thanks for the help
How to convert ASCII value to a character in Objective-C?
NSString has a method to get the characters in an array:
NSString *string = "This is some string. It has spaces, punctuation, AND capitals.";
unichar *buffer = malloc(sizeof(unichar) * [string lenght]);
[string getCharacters:buffer range:NSMakeRange(0, [string length])];
If you check the definition of unichar, it's an unsigned short.
hii every one
is there a way to get the character count in a string in obj c?
like how does the SMS app determine how big of a bubble the text view sends and receives? thanks a lot
You can use something like this:
NSString *str = #"Hello World!";
NSUInteger len = str.length;
If it is NSString then use str.length
If it is c string then use strlen(cString)
If it is a NSString then
[string length];
Not sure if you are talking about multi-bytes characters
length
Returns the number of Unicode
characters in the receiver.
- (NSUInteger)length
Return Value
The number of Unicode characters in
the receiver. Discussion
The number returned includes the
individual characters of composed
character sequences, so you cannot use
this method to determine if a string
will be visible when printed or how
long it will appear.
NSLog(#"Length of your string is %d",[yourString length]);
I have on one string like #"K_h_10_K_d_10_K_c_13_T_c_13_T_s_13"
I separate them by #"_"
using appCardString=[substringAppCard componentsSeparatedByString:#"_"];
then I have to convert them in to char and want to put in char[] ....
how can I do that ..
please help me ....
It's crashing here
appusedFaces[i]=[[NSString stringWithFormat:#"%#",[appCardString objectAtIndex:i]] charValue];
This will work:
appusedFaces[i]=[[appCardString objectAtIndex:i] characterAtIndex:0];
Though you should add a check that the string has at least one character. You should also be aware that char can only hold character codes up to 255 (unichar can handle any Unicode character).
It also looks like you have some numeric codes in your test string. Checking if the string has more than one character and then calling [[appCardString objectAtIndex:i] intValue] for those characters will handle these.
I know it must be a very simple thing to do but I've never had to treat strings before (in Objective-C) and apparently there's not RegEx on Cocoa-Touch.
Well, the situation is:
I have a text field to get a value (money, such as 32.10 for instance).
The problem:
If the user types in a symbol such as #, /, # etc. my app will crash.
The Question: How can I treat this string to remove the symbols if there are any?
you can try this:
NSString *s = #"12.827##584";
NSCharacterSet *removeCharSet = [NSCharacterSet characterSetWithCharactersInString:#"/:##"];
s = [[s componentsSeparatedByCharactersInSet: removeCharSet] componentsJoinedByString: #""];
NSLog(#"%#", s);
You do get regex in Cocoa Touch.
Here's a good discussion of the varying degrees of regex power in iOS, the blocks example at the end should get you most of the way there.
http://volonbolon.net/post/861427732/text-handling-in-ios-4
I understand you're trying to figure out the number included in the UITextFields's text property and assign it to a float variable.
Try using an NSScanner for this:
NSScanner* textScanner = [NSScanner localizedScannerWithString:textfield.text];
float* floatValue;
[textScanner scanFloat:&floatValue];
floatValue now contains the parsed float value of your textfield.
How to convert integer into hexadecimal value programmatically in iphone?
Here's one way:
int myInteger = 12345;
NSString* myString = [NSString stringWithFormat:#"%x", myInteger];
myString will contain what you've asked for, so it may help to elaborate
on how you need to use the result.