nsstring

I want to check if a particular string is just made up of spaces. It could be any number of spaces, including zero. What is the best way to determine that? Alexsander Akers NSString *str = @" "; NSCharacterSet *set = [NSCharacterSet whitespaceCharacterSet]; if ([[str stringByTrimmingCharactersInSet: set] length] == 0) { // String contains only whitespace. } Try stripping it of spaces and comparing it to @"": NSString *probablyEmpty = [myString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]]; BOOL wereOnlySpaces = [probablyEmpty isEqualToString:@""]; It's significantly

申请内购部分略。。。。。。。 代码部分 1 //准备工作 [[SKPaymentQueue defaultQueue] addTransactionObserver:self]; <SKPaymentTransactionObserver,SKProductsRequestDelegate> //遵循代理 打开支付开关 如下图: 2 //商品查询 msg 是商品编号 if ([SKPaymentQueue canMakePayments]) { NSLog(@"用户允许内购"); NSArray *product = [[NSArray alloc] initWithObjects:msg,nil]; NSSet *nsset = [NSSet setWithArray:product]; //初始化请求 SKProductsRequest *request = [[SKProductsRequest alloc] initWithProductIdentifiers:nsset]; request.delegate = self; //开始请求 [request start]; } else { NSLog(@"用户不允许内购"); } 3//请求到商品信息 然后在里面验证 在发起支付 #pragma mark - SKProductsRequestDelegate -

When creating a string using the following notation: NSString *foo = @"Bar"; Does one need to release foo ? Or is foo autoreleased in this case? Compiler allocated strings (of the format @"STRING") are constant, and so -retain, -release, and -autorelease messages to them are ignored. You don't have to release or autorelease foo in this case (but it won't hurt). As mentioned in the docs http://developer.apple.com/documentation/Cocoa/Conceptual/MemoryMgmt/Tasks/MemoryManagementRules.html You take ownership of an object if you create it using a method whose name begins with “alloc” or “new” or

This question already has an answer here: How can I convert an int to an NSString? 4 answers I want to convert a random int number in the NSString and then assign the NSString to another NSString but it crashes the app I am doing the following int mynumber =(arc4random() % 1000 ); unique = [NSString stringWithFormat:@"%d",mynumber]; NSLog(unique) NSString*test=unique; it gives crash when i write last line; It also prints values when I nslog the unique string. Tendulkar If you want to change the int to string NSString *strFromInt = [NSString stringWithFormat:@"%d",yourintvalue]; This also works

My app encrypts and decrypts (or it should) an NSString (the text to be encrypted / decrypted) with another NSString (the keyword) using aes 256-Bit Encryption. When I run my project and run the encrypt method, nothing gets encrypted the textfield just clears itself. Here is the code I have: -(void)EncryptText { //Declare Keyword and Text NSString *plainText = DataBox.text; NSString *keyword = Keyword.text; //Convert NSString to NSData NSData *plainData = [plainText dataUsingEncoding:NSUTF8StringEncoding]; //Encrypt the Data NSData *encryptedData = [plainData AESEncryptWithPassphrase:keyword];

Hi all i want extract the last part from string which is a four digit number '03276' i:e http://www.abc.com/news/read/welcome-new-gig/03276 how can i do that. You can also use NSString *sub = [@"http://www.abc.com/news/read/welcome-new-gig/03276" lastPathComponent]; If you know how many characters you need, you can do something like this: NSString *string = @"http://www.abc.com/news/read/welcome-new-gig/03276"; NSString *subString = [string substringFromIndex:[string length] - 5]; If you just know that it's the part after the last slash, you can do this: NSString *string = @"http://www.abc.com

I am accepting an NSString of random size from a UITextField and passing it over to a method that I am creating that will capture only the last 4 characters entered in the string . I have looked through NSString Class Reference library and the only real option I have found that looks like it will do what I want it to is - (void)getCharacters:(unichar *)buffer range:(NSRange)aRange I have used this once before but with static parameters 'that do not change', But for this implementation I am wanting to use non static parameters that change depending on the size of the string coming in. So far

What formatter is used for boolean values? EDIT: Example: NSLog(@" ??", BOOL_VAL); , what is ?? ? One way to do it is to convert to strings (since there are only two possibilities, it isn't hard): NSLog(@" %s", BOOL_VAL ? "true" : "false"); I don't think there is a format specifier for boolean values. I would recommend NSLog(@"%@", boolValue ? @"YES" : @"NO"); because, um, BOOL s are called YES or NO in Objective-C. Use the integer formatter %d , which will print either 0 or 1 : NSLog(@"%d", myBool); In Objective-C, the BOOL type is just a signed char. From <objc/objc.h> : typedef signed char

What is the difference between copy and retain for NSString ? - (void)setString:(NSString*)newString { string = [newString copy]; } Malaxeur In a general setting, retaining an object will increase its retain count by one. This will help keep the object in memory and prevent it from being blown away. What this means is that if you only hold a retained version of it, you share that copy with whomever passed it to you. Copying an object, however you do it, should create another object with duplicate values. Think of this as a clone. You do NOT share the clone with whomever passed it to you. When