Objective-C

The advantage of the Objective-c language is that we are more flexible when writing code, such as we can forward the message to the object we want, or swap the implementation of a method at random. This feature means that objective-c requires not

OBJECTIVE-C implementation of MD5 and SHA1 algorithm is relatively simple, you can directly call the system's C/s + + shared library to implement the callMD5 is the message Digest algorithm 5 (Information-Digest algorithm 5), which is used to ensure

Previously implemented in the blog SHA1 Security has not met the needs of users, today the implementation of the sha224/sha256/sha384/sha512 attached. The SHA that Secure Hash algorithm (safe hashing algorithm) has many kinds of different bit number

Problem: When I do user login, the background API needs to MD5 the encryption of the number and request time of the merged strings, so on the GitHub to find an encrypted frame, link: https://github. (ox) Com/paulery2014/cocoasecurity, I wrote a

(1) Create an array and output it. To create an array directly using Nsarray, [arr count] calls the method to compute the length of the array. [Arr objectatindex:i] is an object that invokes a method to get a index position. #import #import

For NSString, there are many practical methods, such as: case conversion, prefix matching, string concatenation, formatting strings, and so on. Let's take a look at the following: #import int main (int argc, const char * argv[]) {@autoreleasepool {

A dictionary is a special type of OC, and its function is very powerful. is an important part of foundation. Let's Learn: #import int main (int argc, const char * argv[]) {@autoreleasepool {//INSERT Co De here .../* Dictionary: 1. Memory is not

When Apple released Xcode7, it not only upgraded the SWIFT programming language to version 2.0, but also made a number of upgrades to objective-c, including the introduction of __nonnull/__nullable. Among them, for the OBJECTIVE-C programming

@interface Nsarray (Reverse) -(Nsarray *) Reversedarray; @end @interface Nsmutablearray (Reverse) -(void) reverse; @end @implementation Nsarray (Reverse) -(Nsarray *) Reversedarray { Nsmutablearray *array = [Nsmutablearray

Factory method Mode:Defines the interface that creates an object, letting subclasses decide which class to instantiate. The factory method delays the instantiation of a class to its subclasses. Almost all applications written in object-oriented

Turn from: Http://stackoverflow.com/questions/8927727/objective-c-arc-strong-vs-retain-and-weak-vs-assign Http://rdcworld-iphone.blogspot.in/2012/12/variable-property-attributes-or.html BJ Homer to Strong/weak reference gave a very image of the

Procedure to run: 1, after the program started, find the main function--------program entrance A Application object was created in the main function, and a delegate proxy was created for the object. 2, jump to application of the. m file, * Create

11.1 Using attribute values (@property) 11.1.2 simplifies implementation code @synthesize is a new compiler feature that represents the access code that created the property. When @synthesize rainhandling is encountered, the compiler speaks of

Reprint please indicate the source: http://blog.csdn.net/zhangxingping Threads In addition to providing exception handling mechanisms, OBJECTIVE-C provides thread synchronization capabilities. Exception handling is described in the previous

Using the taxonomy in Object-c is a compile-time tool that allows us to extend it by adding a method to a class (but not adding new instance variables through category), and we do not need to access the code in the class. This is a bit like using a

Recently researched the ability to sign in on an iOS phone. The SHA1 algorithm is used because of encryption. The net also did not find the direct example, the final reference StackOverflow on the big God, completed the encryption

A lot of programmers who want to develop iOS, or are developing iOS, have done Java or C + + before, when the first time to see OBJECTIVE-C code is a headache, objective-c code in the syntax and Java, C + + has a big difference, Some students will

Shallow copyA shallow copy is a copy of the memory address, so that the target object pointer and source object point to the same piece of memory space. Such as: 12 char* str = (char*)malloc(100);char* str2 = str; A

Objective-c, the strong and weak pointers under ARC are explained in principleTip: The "instance variable" in this article is "member variable" and "local variable" isFirst, IntroductionARC is a new feature that has been added since iOS 5,

In my understanding, an object is a piece of memory. This article will discuss the layout issue of an objective-C object in the memory, if a class does not need to inherit some of its specific behaviors from nsobject, it does not need to inherit