php - Use of undefined constant 0 - assumed ' 0' when using substr

In PHP version 5.6, the substr function is used to intercept strings. The code is as follows {code...} Use of undefined constant 0 - assumed ' 0' appears. The online solution is to modify error_reporting in php.ini to turn off the notice. But what is this essential question? ? like...

迷茫 2017-06-10 09:47:52 0  2  1233

Regarding whether it is necessary to create a new Base.php. . . .

Isn't there a public common class in thinkphp5? Moreover, there is also a common class definition under the default APP. If there is no common under the module, it will be inherited under the APP. After the common.php file is created under the controller module, it can be inherited directly without ...

A.zl 2017-09-09 22:03:07 0  1  1148

java - Anonymous inner classes and inherited classes, why is there a difference when implementing ClassLoader

I was looking at the Java virtual machine recently, and the class loader section gave this example: {Code...} In short, it uses a custom class loader to load a class, and the returned class is the same as the class loaded by the SystemClassLoader that comes with the jvm. different. So if you use a c...

PHP中文网 2017-05-17 10:07:45 0  1  784

This is a big php programming question. I have no choice. Please help.

Define a parent class Person (person), including two attribute members xm (name) and xb (gender) and a constructor. xm and xb cannot be read and written directly in the main program. The name and gender are initialized in the constructor. . Define a subclass teacher (teacher) inherited from Person, ...

有为鱼 2019-01-08 15:02:44 0  3  1108

c++ - Qt connect function reports error?

{Code...} Both connections reported errors {Code...} The classes used all inherit QObject and contain Q_OBJECT. Using the old syntax still reports errors.

高洛峰 2017-06-19 09:07:26 0  2  1338

java - Is there any elegant way to handle calls from different sources differently for the same method?

When I was writing a control. There is a class subViewPager that inherits ViewPager. I need to use the getCurrentItem() method of this ViewPager in another place, which means to get a certain coordinate of this control. But because my ViewPager is for special effects, let it...

淡淡烟草味 2017-07-03 11:42:06 0  2  1265

How to directly execute the inheritance chain's base class in Javascript (OOP)?

I'm dealing with an inheritance chain of 3 extendable classes. Renderer (base) ->Mailbox (child) ->MailboxInbox (final child) Each of them has its own render method. Children just override the render method of the renderer (Base) and finally they should use the render method of the renderer (B...

P粉718165540 2024-01-10 17:20:07 0  1  404

box-sizing not inherited through DETAILS element?

Using the common technique of inheriting box-sizing, even if the DETAILS element has the correct value, that value is not inherited by the DETAILS element's child elements. In the example code snippet, the DIV outside the DETAILS element inherits box-sizing (as expected and required), but the DIV in...

P粉618358260 2024-02-21 16:31:32 0  2  385

Python - Return a new instance of itself through a class method

Define a class A and have a method with its own ID + 1. The code is as follows: {code...} Define instance x as class A with an id of 1 and print x.id: {code...} Now I want to create An instance y, which is also a class A, is created through the newid method of class A: {code...} You can get the accu...

漂亮男人 2017-05-18 10:53:17 0  2  652

The examples in this section report an error when typed.

When using use to import a namespace, a syntax error will be displayed, or it will be displayed that the class in the namespace has been defined. The PHP version is 7.2.10.

宝怡 2019-07-23 13:28:20 0  5  1347

How PHP interfaces actually change the behavior of classes

According to the PHP documentation, object interfaces allow you to create code that specifies which methods a class must implement without defining how those methods are implemented. So, the interface is like a class with predefined methods, which still need to be accessed using -> notation. Howe...

P粉289775043 2023-09-02 23:49:28 0  1  623

javascript - Babel's problem with inheriting predefined class conversions

I wrote a class that inherits Array in ES6 and overridden the push method. However, after converting it to ES5 using Babel, I found that the method called is still the original push method: .babelrc:: {code...} ES6 code before compilation: { Code...} ES5 code compiled by babel: {Code...} Actual...

曾经蜡笔没有小新 2017-05-19 10:30:16 0  1  540

How to use the tp5 model result method, and what values ​​can its parameter $type take?

Use the tp5 model result method (actually a method inherited from the Jump class) to return data to the front end. I only know that the parameter $type can be "json". I wonder if there are other parameter values? After testing, when $type is "", "array", or "collec...

phpcn_u16587 2019-07-16 21:24:57 0  0  1044

How to automatically load custom classes in laravel 5.2?

1. Define a class QrCode.php {code...} under app\Libraires 2. Call the method of this class {code...} 3. Report error message {code...} 4. Try to solve the problem by using composer dump -autoload passed, but the class still cannot be loaded. How can I automatically load the custom class...

巴扎黑 2017-05-16 16:49:26 0  2  511

javascript - Can class attributes and methods be separated into files in ES6?

To define a class in es6, you can use {code...} When there are more and more attribute methods in class A, you will find that the entire file has a large amount of code. Can some properties and methods be divided into a single file (for example, x and mx are divided into an x.js file, y and my are d...

仅有的幸福 2017-06-28 09:28:59 0  1  825

python - pymysql reports error 1146 The xls table failed to import into the database. I don't know where the problem lies.

Python 4.3.0 defines a class to operate the local database, and then defines two functions to import the corresponding two tables. The strange thing is that the first function input_HA() can be used and the form is imported successfully, but the second input_ImpactList() does not work. Can anyone he...

漂亮男人 2017-05-18 10:55:11 0  1  1223

What the hell

Use of undefined constant USER_ID - assumed 'USER_ID' (this will throw an Error in a future version of PHP)

笑的承诺-雷 2018-12-02 09:25:32 0  1  1045

How to autowire an interface in Comparator class

Using springboot and mongo's repository, I defined a Comparator class and wanted to implement my own object comparison method. The code is as follows: {Code...} However, in this case, storyRepository is null. How should we deal with this? Thanks

大家讲道理 2017-06-28 09:24:59 0  1  956

Android bug - In Android, why can't intent initialization be written outside the method?

beginner. Today I wrote a code to jump between activities, using an explicit intent, but I defined an intent member variable in the class, and when I used it in the method, the program crashed. Why is this? {Code...} The above code, but the error message is: Caused by: ...

伊谢尔伦 2017-05-16 13:35:09 0  3  929

How to ensure full scrolling text coverage when using CSS property 'Overflow: scroll' on a div

I'm new to programming and currently trying to make a simple one page website using HTML/CSS and JS. I have a CSS class called 'general_container' in which I write text, this class is also defined in CSS as 'div_text' (code for both is provided below): .general_container{margin:min(1vw,1vh )min(1vw,...

P粉321584263 2023-08-16 00:13:42 0  2  566