objective-C中代码块中的本地变量，__block前缀和static全局变量

代码如下： typedef void (^fun) (double a, double b); double c = 3; fun multiply = ^(double a, double b) { c = a * b; }; multiply(4, 5); printf("c = %f\n", c); 注意到这里用了一下typedef，然后问题就...

巴扎黑 2017-04-24 09:13:55 0  1  581

Usage of return

What is the specific usage of return?

意外 2019-03-18 23:45:09 0  2  1210

python method call

Part of the code: {Code...} Why do I call inwaiting() in the read_data() method and an error is reported, telling me that it has no attribute 'inwaiting()'. It is normal to write ser.inwaiting() outside the method. Isn't it already? Have you passed the reference to the serial object into the method?...

学习ing 2017-06-12 09:23:06 0  2  1135

How does a PHP static method call a non-static method of the parent class?

1. this calls the parent class method: 2. self calls the parent class method: 3. parent calls the parent class method: Is there no way for a subclass static method to call a parent class non-static method?

淡淡烟草味 2017-06-08 11:01:40 0  5  1114

angular.js - angularJS ng-style用法

angularJS ng-style usage thank you

phpcn_u1582 2017-05-15 16:58:40 0  1  822

How to use the teacher's web page HTML editor

How to use the teacher’s web page HTML editor

Simple 2018-08-17 22:05:53 0  1  1467

The TP6.0 system variable __PUBLIC__ cannot be used. What is the current usage?

TP6.0 The system variable __PUBLIC__ cannot be used. What is the current usage?

听风online 2019-06-05 16:52:31 0  0  790

javascript - angular $state.transitionTo usage explanation

Angular $state.transitionTo usage explanation

阿神 2017-05-19 10:24:01 0  1  748

Can mysql5.5 use match against usage?

Can mysql5.5 use match against usage? Why no data is returned when I test the data set: user_id user_tags1 Swimming Running Basketball 2 Football Table Tennis 3 Basketball Shot Put Football

Nine 2022-05-19 18:21:55 0  0  1311

What is the function of MARKDOWN syntax?

Please tell me, teacher, with HTML, what is the role of MARKDOWN syntax?

谭振威 2022-07-16 12:33:37 0  1  772

Does the factory pattern refer to using static methods to call properties and methods in the singleton pattern?

Does the factory pattern refer to using static methods to call properties and methods in the singleton pattern?

王志恒 2018-06-16 16:53:32 0  0  1314

javascript - js method calling, method self-tuning, rewriting

How is the toString method called? ? ? Ask God for answers

过去多啦不再A梦 2017-05-19 10:09:59 0  4  542

How to use password_hash algorithm

I have been studying the use of password_hash to process passwords into the database these days, but I don’t know how to use it to process passwords entering the database. MD5 can be executed directly on the database statement: $query = "INSERT INTO member(urs_name,password,rt_time) VALUES ( '{...

镜花水月 2017-09-21 16:22:32 0  1  1146