Programmer Think

The overall structure of ORC documents is as follows: The searching and indexing of data in orc file structure is essentially three-level filtering: file level, Stripe level and Row Group level. In this way, the data actually to be scanned and read can be reduced to part of the RowGroup of part of the Stripe without scanning the whole file. ...

catalogue I Overview of generics II Define and use classes with generics III Define and use methods with generics IV Define and use interfaces with generics V Generic wildcard I Overview of generics When we learned about the collection, we all know that any Object can be stored in the collection. As long as the objects are stored in t ...

Hello, I'm A bowl week , a front end that doesn't want to be drunk. If you are lucky enough to get your favor, I am very lucky~ Write in front When we write Vue2, the way to write components is to use the Options API. The feature of this way is to write corresponding function modules in the corresponding attributes, such as defining data in ...

The implementation of Lifecycle is similar to ViewModel, which uses fragment to realize its functions. By adding a fragment to the activity, the fragment can receive various life cycle callbacks. The following source code uses version 2.2.0 Introduction to using method I'm not going to talk too much about the usage of lifecycle here. Un ...

prefaceAn old project of the company didn't do the verification before code submission. After I got it, I thought about the old project and didn't have time to help it with these. Anyway, I just changed a little something; Try to follow its code style and submit it after writing;Until one day, another person joined in. Good guy, something happe ...

I Foundation typeNever:Throw exceptionFunction expression with no return value🌰// The function returning never must have an unreachable end point function error(message: string): never { throw new Error(message); } // The inferred return value type is never function fail() { return error("Something failed"); } // The function returni ...

1) Let the user input the content of multiplying any two integers (such as "2 * 3") to output "2 * 3 = 6". For example, the operation condition is: Let's finish it step by step. Complete the input first: strs = input() Assuming that we input "2 * 3", we need to split the two values before and after the asteri ...

Initial value of weight (the pit here is too deep. This article is just an introduction to in-depth learning and will not pursue theory in detail) In the learning of neural network, the initial value of weight is particularly important. In fact, what kind of weight initial value is set is often related to the success of neural network lea ...

Animation function encapsulation Animation implementation principle Core principle: continuously move the box position through the timer setInterval(). Implementation steps: Get the current position of the boxAdd 1 movement distance to the current position of the boxUse the timer to repeat this operation continuouslyAdd a condition to ...

At present, I haven't involved in webui automatic testing in my work, but in order to improve my technology, it's not harmful to learn more. There's no more nonsense. At present, the mainstream webui testing framework should still be selenium. Considering maintainability, expansibility and reusability, we use PO mode to write our script, This d ...