Programmer Think

catalogue 1, Basic usage of array 1. What is an array 2. Creation of array 3. Use of arrays 2, Array as an argument to a method 1. Get familiar with JVM memory area division 2. One question:  3.null  4. Array as the return value of the method 3, Some exercises of array 1. Array to string 2. Copy of array 3. Allocate elements f ...

1. Classes and objects 1.1 what is the object? Everything is an object, and everything that exists objectively is an object 1.2 what is object-oriented? The action of paying attention to objects is called object-oriented For example, I'm going to the supermarket to buy fruit. Fruit is an object. I pay attention to its type, size, acidity a ...

I keyword **Concept: * * words with special meanings in Java are called Keywords for Java There are 51 + 2 keywords in Java 51 keywords and 2 reserved words (goto const - > not available now) Give meaning (may be given in the future) **Note: * * is composed of lowercase words, and is in the corresponding editing tool Is highlighted in ...

1. Three elements of network programming Network programming refers to the program running on different computers under the network communication protocol, which can carry out data transmission 1.1 IP address IP address: it is the unique identification of the device in the network IP addresses fall into two categories: IPv4: assign a 32bit ...

Java one-dimensional array and two-dimensional array definition and traversal, how to add and delete one-dimensional array with code preface In this article, we will introduce the use of arrays. We often use the double variable name when storing a student's grades, but in this way, we can only store one data at a time. In reality, there ...

When I think my code is safe, wait... catalogue Basic concepts of multithreading Basic concepts: program, process and thread Understanding of single core CPU and multi-core CPU ​  Parallelism and concurrency Advantages of using multithreading ​  When do I need multithreading ​  Creation and use of threads ​ Method 1 of cr ...

I studied a few days ago AQS source code In order to deepen the impression, today we will implement a lock based on AQS 1. Implement non reentrant lock based on AQS Previously, we learned the source code of AQS and learned that a custom AQS needs to rewrite a series of functions and define the meaning of the atomic variable state. In the fo ...

1, HTML+CSS 2, JavaScript 3, JQuery, BootStrap framework 4, XML 5, Web overview and Tomcat server 5.1 preparation before using tomcat Install and configure jdkDownload and unzip TomcatConfigure environment variables Variable name: CATALINA_HOME Variable value: path just installed 5.2 directory structure of Tomcat Directory nameeffectbin ...

catalogue 1, Core requirements 1. Simple login 2. Management end Organize books (this function is extensible) Consult books Add books Delete books Print book list sign out 3. Client Query books Borrow books Return books sign out 2, Class design 1. Create book related classes Create a package book first 2. Create operation re ...

The essence of annotation When talking about the essence of annotation, the simplest way is to decompile. See the essence. The code is as follows: import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; @Retention(RetentionPolicy.RUNTIME) public @interface Foo{ String[] value(); boolean bar(); } Use the ...