cdr traps

Sorting and Compare traps in Objective-C Campare trap NSString has multiple compare related methods:-(NSComparisonResult) compare :( NSString *) string;-(NSComparisonResult) compare :( NSString *) string options :( NSStringCompareOptions) mask;-(NSComparisonResult) compare :( NSString *) string options :( NSStringCompareOptions) mask range :( nsange) compareRange;-(NSComparisonResult) compare :( NSString *) string options :( NSStringCompareOptions) m

One of Asp for JScript traps: character escaping and jscript escaping Incorrect usage: Cause:Because I obtains the value output by path1 and \ is an escape character, I actually obtains the value C: mydirimg, whileAlthough the value of j is C: \ mydir \ img, j is still a js variable, SO \ is still an escape character. It looks like this: Correct usage:

causes the program to crash, which often occurs when the parent class has a kvo, and the parent removes it once in Dealloc, The subclass is again in the case of a remove. Don't think this is a rare occurrence! It is possible when you encapsulate the framework open source for others or collaborative development with multiple people, and this crash is hard to find. I don't know if you found out, the current code in the context field is nil, that can be used to identify whether the KVO is supercla

the program. But using assertions is dangerous, and once the system fails, it hangs.Five, the thinking of the AssertSince the assert is intended to debug a test program and is not used in a formal production environment, it should be considered better to test juint instead of using it, and the juint relative to the Assert key provides more functionality. Of course, debug testing can be done entirely through IDE Debug.In this view, the future of the assert is dim. Therefore, you should avoid usi

Detailed description of deadlock traps when using Python + Java to call Shell scripts, pythonshell Preface A recent requirement is to regularly determine whether the execution conditions of a job meet and trigger a Spark job. When writing a Spark job, it is encapsulated into a Jar package and then passed in the required parameters for execution using Shell scripts, considering that the judgment condition logic is complex, it is not conducive to develo

Common pitfalls and traps for pure Socket (BIO) long link programming, socketbioThis article is purely a summary of my personal experience. The pseudocode is also coded on the whiteboard when I write an article. There may be logic problems. please correct me. Thank you. Internet (Global Internet) is produced by communication between countless machines based on TCP/IP protocol families. TCP/IP protocol families are implemented in four layers: link laye

This trap comes from a requirement that the data needs to be processed asynchronously in the background. After processing, the event that is triggered to be processed is probably written as follows: EmployeeCollection data = += The code is quite simple, and the traps are also in it. Suppose DalHelper. fill (data) throws an exception. raiseEventLoaded () won't be executed and depends on data. the Loaded Event code will not be executed either. This is a

1 values equal, objects are equal by default? What are the default rules that determine the existence of a reference type in a. NET container? Determines whether the pointer values are equal. private static list The Model class used: public class MyObject {public int Value {get; set;} } Here are 1 tests: Even if value is equal, the memory address of Instance2 and Instance1 is not equal! bool IsExistence1 = list. C

We will meet a variety of interviews, some even the HR specifically for you to set the barrier, in the Python interview is also, whether you are candidates for Python web development, crawler engineers, or data analysis, or automated operations, these Python interview basic Questions ten traps Maybe you will encounter, Today's Python training is summed up in case you're ready to receive!Question 1: How can I modify the following Python code so that th

Window.getwindow parameters cannot be null, that is, doworker.target as control fails, doworker.target is not a window at all, nor is it a control. How is that possible?!! The code is clearly written in a custom control. And there is another one in this control that is called the Run method, the parameters are similar, there is no problem, running smoothly. Why did this call fail?After the trace debugging, found that the original problem is in place of the call. When the first parameter doworke

This article mainly introduces the use of parameters in Python functions and the traps of default parameters. In this article, function parameters are divided into required parameters, default parameters, variable parameters, and keyword parameters, you can refer to the functions in C ++ to set the default parameters. Java is not supported and can only be implemented through overloading. python can also set the default parameters, the biggest benefit

Spring and MyBatis are integrated to automatically generate text-type traps in the Code. springmybatis After the integration of Spring and MyBatis, use the Automatic Generation Code tool to generate the dao and mapper configuration files. The generation steps are as follows (taking Intelli idea as an example ). 1. Compile generatorConfig. xml. 2. Configure the following maven running command. 3. Run generatorcode. Problem description Assume that tex

Find the duplicate number. The first reaction is MAP (which they use for hash), which is easy to write (I am a pointer to the weak slag). However, some traps have been found during actual application, leading to several wa. the principle is very simple: Create a table, convert it to a number, ignore the horizontal bar, add it to the MAP, and automatically open the memory ++ according to the features automatically managed by the MAP (automatically keep

The first four data types of native data are discussed;This article mainly talks about the last four data types:Single-precision float: float;Double-precision floating point: double;Character Type: char representation: char is the abbreviation of character. A character represents a single character. For example, a is a letter or a Chinese character, which is enclosed by single quotation marks. For example, char a = 'B'; char B = 'zhang ';Boolean: boolean indicates that the boolean type has only

Python traps and notes frequently encountered during development recently encountered some pitfalls when using Python, such as using datetime. datetime. now () is the variable object used as the default parameter of the function, and the module cycle dependency. Record it here to facilitate future query and supplement. Avoid using mutable objects as default parameters When using a function, default parameters are often involved. In Python, when a mut

, from system logon to online banking, you may encounter all the security risks and solutions in your daily life. In addition, since we have been introducing many software security issues in the past and ignoring some hardware security features, in this article, we will also introduce you to a variety of products with outstanding hardware security performance, such as the ability to lock hard disks so that they can only be used on the local computer. Traps