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1. Top results related to what is objective-c used for in reading books

   • What is the proper way of reading/writing NSDictionary and NSArray to a file in Objective-C in 2018?

     Top Answer

     Answered Aug 02, 2018 · 4 votes

     It's not quite as concise, but you can use the class methods on NSPropertyListSerialization to convert between plist objects (including NSArray and NSDictionary) and NSData, then use API on NSData to read and write from files.

     For example, reading in from a file might look like:

     NSData *fileData = [NSData dataWithContentsOfFile:@"foo"];NSError *error = nil;NSDictionary *dict = [NSPropertyListSerialization propertyListWithData:fileData options:NSPropertyListImmutable format:NULL error:&error];NSAssert([dict isKindOfClass:[NSDictionary class]], @"Should have read a dictionary object");NSAssert(error == nil, @"Should not have encountered an error");

     Likewise, writing out to a file is similar, but with the two steps reversed:

     NSError *error;NSData *data = [NSPropertyListSerialization dataWithPropertyList:dict format:NSPropertyListXMLFormat_v1_0 options:0 error:&error];NSAssert(error == nil, @"Should not have encountered an error");[data writeToFile:@"foo" atomically:YES];

     While this takes a few more keystrokes to write, it's…

     • More expressive of the process that is actually occurring (conversion, then file I/O)
     • Clearer about the what actually ends up in the file foo (property list data in XML v1.0 format)
     • More helpful when debugging (out error pointers give failure reasons; NSData has them for I/O as well on other more verbose methods)

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     1/5

   • What is dealloc in objective C

     Top Answer

     Answered Jul 16, 2010 · 15 votes

     The dealloc method is called on an object when it's retain count has reached zero. Retain counts are increased by one for each retain call, and reduced once for each release call. The autorelease schedules a future release call when the current NSAutoreleasePool is drained, typically at the end of an event cycle, but you can set up your own NSAutoreleasePools on memory intensive operations. (See the NSAutoreleasePool docs for details.)

     What should you put into dealloc? You should put a release for each member object the object of that class retains.

     A couple things make this easier. The nil object will quietly ignore any messages sent to it, so [foo release] when foo = nil is not a bug. However, releasing an object twice can cause serious issues. My (hardly unique) solution to this is to explicitly set whatever I just released to nil, whenever I release it. In fact, I put the nil assignment on the same line as the release so I can grep for "release" and find places I missed. Example:

     @interface MyClass { Foo *foo; Bar *bar; NSInteger baz;}-(void)dealloc;@end@implementation MyClass-(void)dealloc { [foo release]; foo = nil; [bar release]; bar = nil; [super dealloc];}@end

     I'll assign nil to a variable even when that variable is about to go out of scope or the object is about to go away. Why? If another object of the same class is allocated in the same memory space after I've released this one, it guarantees there will be no dangling pointers the new object might accidentally use and make debugging a nightmare. (See also NSZombieEnabled for debugging help.)

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     2/5

   • What is 'for' used for in bootstrap form label?

     Top Answer

     Answered Jun 06, 2016 · 13 votes

     If you click on the label with your mouse, then the cursor will automagically jump to the input specified in the 'for' attribute. It's really useful, don't remove it.

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     3/5

   • what is ^ used for in ruby?

     Top Answer

     Answered Jul 13, 2012 · 29 votes

     In most programming languages, ^ is the XOR operator (Exclusive Or in Wikipedia). XOR is one of the most essential operations in the CPU, it often employed to zero registers (think of a ^= a) because it is fast and has a short opcode.

     For the power function, you have to use e.g. ** (e.g. in ruby), java.lang.Math.pow, math.pow, pow etc.

     In fact, I couldn't name a programming language that uses ^. It is used in LaTeX for formatting (as superscript, not power function, technically). But the two variants I see all the time are ** (as the power function is directly related to multiplication) and pow(base, exp).

     Note that you can compute integer powers of 2 faster using shifts.

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     4/5

   • What Is an IEnumerator In C# and what is it used for in Unity?

     Top Answer

     Answered Nov 17, 2021 · 8 votes

     what is the use of IEnumerator function

     IEnumerator there isn't a function, it's a return type. C# doesn't have functions either (but I know what you mean) - in C# we call them methods.

     IEnumerator being so called implies it is an interface, so any class that implements the IEnumerator interface can be returned by this method

     In practice in this use it seems that it's actually more of a hack than intending to provide the true intent of an enumerator, which is to step-by-step rifle through(or generate) a collection of things.

     When you use a yield return statement within a method "some magic happens" whereby it's not a return in the classic sense, but creates a facility whereby the code can resume from where it left off (calling for the next item out of the returned enumerator will cause the code to resume from after the yield, with all the state it had before, rather than starting over).

     If you look at the MSDN example for yield:

     public class PowersOf2{ static void Main() { // Display powers of 2 up to the exponent of 8: foreach (int i in Power(2, 8)) { Console.Write("{0} ", i); } } public static System.Collections.Generic.IEnumerable<int> Power(int number, int exponent) { int result = 1; for (int i = 0; i < exponent; i++) { result = result * number; yield return result; } } // Output: 2 4 8 16 32 64 128 256}

     The loop is controlled by i; if this wasn't a yield return then this wouldn't function as intended (it couldn't return an enumerator for a start but we'll leave that out). Suppose it was just a normal return, the loop would never loop at all; the code would enter, start the loop, hit the return, and just return a number one time and all memory of where the loop was would be forgotten.

     By making it a yield return, an enumerator is returned instead, and a small set of "saved state" is set up whereby the loop can remember the current value of i - each time you ask for the next value, the code resumes where it left off from (ie just after the yield), the loop goes round again and a different value is yielded. This continues up to the max of course.. at which point the returned enumerator says it has no more items

     You could yield forever, too.. If the code can never escape the loop then it will yield/generate forever

     In this case you have to use yield return new WaitForSeconds because that's how WaitForSeconds is intended to work. Yielding gives up an enumerator to the calling method, which is then free to enumerate it. From the docs it looks like this is deliberately done on the next frame, so using yield (perhaps repeatedly) is a way of arranging a block of code that occurs across several frames without having some sort of external state management that remembers where the process is up to and a wordy

     • if state = 1 then close the door and add 1 to the state,
     • else if state = 2 then light the torch and add 1
     • else if state = 3 ...".

     You can just

     • yield,
     • close the door,
     • yield,
     • light the torch,
     • yield ..

     Can't we do this by this process

     Sure, looks reasonable; look at the clock 100 times a second and if 0.5 seconds have passed since you first looked at the clock, spawn the obstacles

     I'd imagine (never used Unity; don't profess to know anything about it other than having read the docs for this one function) that your Update loop has a lot more to be getting on with, so handing a process off to a dedicated wait-then-do is more efficient than spending all your time looking at a clock and carrying out a potentially complicated calc to work out if you should do something; most things in life that start out as poll-every-x-milliseconds benefit from being switched to an "if the event occurs, react to it" way of working

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     5/5

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2. www.geeksforgeeks.org › what-is-objective-cWhat Is Objective C? (Definition, Uses, vs. Swift ...

   www.geeksforgeeks.org › what-is-objective-c

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   Mar 5, 2024 · Objective-C uses a dynamic runtime system that allows objects to be created as well as manipulated runtime and features dynamic binding, which allows method calls to be resolved at runtime rather than compile time.

3. en.wikipedia.org › wiki › Objective-CObjective-C - Wikipedia

   en.wikipedia.org › wiki › Objective-C

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   Objective-C is a high-level general-purpose, object-oriented programming language that adds Smalltalk -style messaging to the C [3] programming language. Originally developed by Brad Cox and Tom Love in the early 1980s, it was selected by NeXT for its NeXTSTEP operating system.

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5. www.readthistwice.com › lists › best-objective-c-books21 Best Objective C Books - Read This Twice

   www.readthistwice.com › lists › best-objective-c-books

   • Cached

   Jan 1, 2003 · This book covers the essentials of Objective-C syntax, as well as memory management, the Objective-C runtime, dynamic loading, distributed objects, and exception handling. With its succinct and well-organized format, it's the perfect resource for programmers who need to get to a solution quickly.

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6. blog.teamtreehouse.com › the-beginners-guide-toThe Beginner's Guide to Objective-C: Language and Variables

   blog.teamtreehouse.com › the-beginners-guide-to

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   • Objective-C The Programming Language
   • Components of The Objective-C Programming Language
   • Stay Tuned

   As you might guess from its name, “Objective-C” is based on the C programming language, with lots of object-oriented features added. It was originally developed in the early 1980s but has really gained in popularity with the rise of iOS. Let’s address some common questions and fears about Objective-C.

   See full list on blog.teamtreehouse.com

   Let’s talk about the code itself. At its most basic level, programming is really about working with data. There are all sorts of types of data we will need to use that range in complexity from simple things like numbers and yes/no values, up to more complex things like pictures or player information for a game.

   See full list on blog.teamtreehouse.com

   There is a lot to cover for even the basic syntax and concepts of Objective-C, so stay tuned for upcoming posts about things like classes, messages/methods/functions, conditionals, and loops! If you want to try some of this out yourself in the browser, check out Build a Simple iPhone App, which includes some exciting Code Challenges to get some pra...

   See full list on blog.teamtreehouse.com

7. www.amazon.com › Objective-C-Programming-RanchObjective-C Programming: The Big Nerd Ranch Guide (Big Nerd ...

   www.amazon.com › Objective-C-Programming-Ranch

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   Jan 1, 2011 · ¿This introduction to programming and the Objective-C language is the first step on your journey from someone who uses apps to someone who writes them. Based on Big Nerd Ranch's legendary Objective-C Bootcamp,¿this book covers C, Objective-C, and the common programming idioms that enable developers to make the most of Apple technologies.

   • 4.5/5 (196)
   • Publish Year: 2011

   • Author: Aaron Hillegass
   • Author: Aaron Hillegass

8. www.computerscience.org › objective-cComputer Programming Languages: Objective-C - ComputerScience.org

   www.computerscience.org › objective-c

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   Aug 4, 2023 · Objective-C is based on C, so developers familiar with C can quickly learn and take advantage of existing C libraries and frameworks. Objective-C uses reference counting for memory management, which can be less efficient than other approaches.

9. People also ask

   Why is Objective-C a good programming language?

   • Objective-C has wide support because it is the primary programming language for Apple’s operating systems. Objective-C may not be suitable for developers who want to create cross-platform apps. Objective-C has a large and active developer community. Compared to other object-oriented languages, Objective-C has a more verbose syntax.

   Computer Programming Languages: Objective-C - ComputerScience.org

   www.computerscience.org/resources/computer-programming-languages/objective-c/

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   Are Objective-C and C++ the same?

   • Objective-C and C++ are not the same programming languages. Although they share similarities, as both are object-oriented and based on C language, they have different features and capabilities. Is Objective-C important in computer science?

   Computer Programming Languages: Objective-C - ComputerScience.org

   www.computerscience.org/resources/computer-programming-languages/objective-c/

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   How does Objective-C work?

   • Objective-C uses a dynamic runtime system that allows objects to be created as well as manipulated runtime and features dynamic binding, which allows method calls to be resolved at runtime rather than compile time. There are various use cases for Objective-C; some of the key uses are mentioned below:

   What Is Objective C? (Definition, Uses, vs. Swift)

   www.geeksforgeeks.org/what-is-objective-c/

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   Why is Objective-C important in Computer Science?

   • Objective-C is an important programming language in computer science, particularly for developing applications on Apple’s macOS and iOS operating systems. It was the primary programming language for developing apps for these platforms for many years and is still in wide use. I graduated from high school in 2020.

   Computer Programming Languages: Objective-C - ComputerScience.org

   www.computerscience.org/resources/computer-programming-languages/objective-c/

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   When did Objective-C become a popular programming language?

   • Steve Jobs and NeXT later popularized it in the late 1980s and early 1990s. Here are three applications of the Objective-C language: Objective-C is the primary programming language for developing apps such as games, productivity tools, and utilities for Apple’s operating systems.

   Computer Programming Languages: Objective-C - ComputerScience.org

   www.computerscience.org/resources/computer-programming-languages/objective-c/

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   What is the difference between Objective-C and other object oriented languages?

   • Compared to other object-oriented languages, Objective-C has a more verbose syntax. Objective-C is based on C, so developers familiar with C can quickly learn and take advantage of existing C libraries and frameworks. Objective-C uses reference counting for memory management, which can be less efficient than other approaches.

   Computer Programming Languages: Objective-C - ComputerScience.org

   www.computerscience.org/resources/computer-programming-languages/objective-c/

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10. developer.apple.com › library › archiveAbout Objective-C - Apple Developer

    developer.apple.com › library › archive

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    Sep 17, 2014 · Objective-C inherits the syntax, primitive types, and flow control statements of C and adds syntax for defining classes and methods. It also adds language-level support for object graph management and object literals while providing dynamic typing and binding, deferring many responsibilities until runtime.