Programmer Think

Java 9 is coming, so we have to sort out Java 8. Official documents: http://docs.oracle.com/javase/specs/jls/se8/html/index.html I. Default and static methods of interfaces The method body can also be written in the interface. The class that implements the interface no longer enforces the implementation of the method, but only needs to add defa ...

1. Prototype of two interfaces In Java, Comparable and Comparator interfaces are used for comparison. So what's the difference between the two interfaces in actual use? Now let's analyze it with examples. Let's first look at the prototype of the two interfaces in JDK. package java.lang; import java.util.*; public interface Comparable< ...

I. Built-in Functions Following is a brief introduction of several: 1. Absolute value of ABS () 2.all() Returns True if all elements of iterable are true (or if iterable is empty). 3.any() returns True if any element of iterable is true. If iterable is empty, return False 4.callable() If the object parameter is tunable, return True or False 5. ...

There are many ways to traverse a map in java, from the earliest Iterator to the foreach supported by Java 5 to Java 8 Lambda. Let's look at the specific usage and advantages and disadvantages of each. Initialize a map first public class TestMap { public static Map<Integer, Integer> map = new HashMap<Integer, Integer>(); } keySet ...

What is thread safety? The more official explanations are as follows: When multiple threads access a class, no matter how the runtime environment is scheduled or how these threads are executed alternately, and there is no need for any additional synchronization or collaboration in the main code, this class can show the correct behavior, so it ...

Steps of Data Mining Data mining usually includes data acquisition, data analysis, feature engineering, training model, model evaluation and other steps. sklearn workflow Sklearns mainly work in dotted frames (sklearn s can also extract text features) Sklearns'main methods fit, fit_transform, transform Transform method is mainly used ...

The last part introduced How to Construct FP Tree Each path of FP tree satisfies minimum support. What we need to do is to find more relationships on one path. Extraction of conditional pattern bases Start with a single frequent element item in the FP tree header pointer table. For each element item, the corresponding conditional pattern base i ...

I. Processes and Threads 1. What is a process? The process is a running program, and has some independent functions. The process is an independent unit for resource allocation and scheduling of the system. 2. Three Characteristics of Process (1) Independence. Process is an independent entity in the system. It can have its own independent resour ...

C#has more than 10 years of history. From the update progress of Microsoft version 1 of 2 years alone, it is extremely vigorous. Asynchronous programming in C#has also undergone several versions of evolution. From today on, a series of blogs have been written to record the development of asynchronous programming in C#Advertisement for a friend ...

The blog Garden is a very good place to learn knowledge. I believe there are many people like me who have been in the blog Garden for 3 years. They do not know how many codes they have copied or how many blogs they have read, but they have never written a single blog.It's a crime. This time I'm going to write a few articles about the reading an ...