Programmer Think

As we all know, JavaScript can generally use typeof to judge the type of a data, except for some special cases, such as typeof null, which will output object. Here is another case. Using typeof to judge the array will also output object. First create an array let arr = [1,2,3] //Or let arr = new Array([1,2,3]) 1.instanceof console.log(arr ...

Java 15 was released in September 2020. Although it is not a long-term supported version, it also brings 14 new functions, many of which are very practical. Java 15 official download: https://jdk.java.net/archive/ Java 15 official documentation: https://openjdk.java.net/projects/jdk/15/ New Java 15 features: JEPdescribeJEP 339Edwards curv ...

leetcode of algorithm interview in Dachang 9. Bit operation Video tutorial (efficient learning): Click to learn catalog: 1. Introduction 2. Time and space complexity 3. Dynamic planning 4. Greed 5. Binary search 6. Depth first & breadth first 7. Double pointer 8. Sliding window 9. Bit operation 10. Recursion & divide and con ...

NSTimer can you really use it? I believe everyone will confidently say: I know! It's simple, but are you sure you're using it right? 1. Use of nstimer A: NSTimer can you really use it? Do you know the circular reference of NSTimer? B: It's not easy, isn't it 👇 This kind of use, So easy! self.timer = [NSTimer scheduledTimerWithTimeInterval ...

In the project, I saw the buried point monitoring, report and log analysis. I'm a little interested and want to make some trouble slowly 1. Data embedding point Monitor the performance of the machine environment and various data such as business processes or logic, and generate corresponding indicators according to these data, then we ca ...

problem I believe many young friends have been asked about the relevant source code in the jdk during the interview. Recently, they have been asked about the source code of ArrayList. They come up to ask whether they have seen the source code of ArrayList and how to remove the elements in ArrayList during traversal, What kind of exception will ...

ExecutorService executorService = Executors.newFixedThreadPool(threadPoolNum, r -> new Thread(r, threadName)); The underlying layer of Executors uses ThreadPoolExecutor. We can understand some behaviors of ThreadPoolExecutor through ThreadPoolExecutor constructor. ThreadPoolExecutor( int corePoolSize, int maximumPoolSize, lo ...

1: Introduction If the reliability of the message is guaranteed? The following problems need to be solved Question 1: the producer can send 100% messages to the message queue! Two unexpected situations: First, the consumer fails to send a message to MQ, and the message is lost; Second, the switch fails to route to the queue, and the routin ...

prefaceHello, I'm Lin Sanxin. In the most popular words, the most difficult knowledge point is my motto. The foundation is advanced, and the premise is my initial intention. Today, I'll talk to you. If the back end really returns 100000 data to the front end, how can we show it gracefully in the front end? (haha, assuming that the back end can ...

[experiment] package com.infuq.tmp; public class Main { public static void main(String args[]) { for (;;) { try { Thread.sleep(5000); } catch (InterruptedException e) { e.printStackTrace(); } } } } In the above code, let the JVM not exit. Let's do so ...