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String class summary String is widely used in Java programming. In Java, string belongs to object. Java provides string class to create and operate string. characteristic Immutability: string is a constant and cannot be changed after creationSharability: string literals are stored in the string pool and can be shared. The string pool ...

1, Common type array int [] For ordinary data type Arrays, several methods are provided in the Arrays class of Java: Arrays.sort(int[] a): arranges the specified array in numerical ordersort(int[] a, int fromIndex, int toIndex): sort the specified range of the array in ascending orderArrays.parallelSort(int[] a): arranges the specified array ...

introduction Talk about the difference between equals() and = =. This is a very classic question. It is not particularly difficult. It is also asked in interviews; However, many young partners have a blank mind during the interview and lose the offer; So here I will introduce the difference between the two in detail, hoping to be helpful to yo ...

Hi, welcome to JasperのBlog! Collection system Collection system considerations List interface: orderly (the order of adding is consistent with the order of traversal), subscript and repeatable elements.Set interface: unordered (the order of adding and traversal are inconsistent), no subscript, and elements cannot be repeated. Colle ...

1.Debug mode 1.1 What is Debug mode Is a program debugging tool for programmers. It can be used to view the execution process of a program or to track the execution of a program to debug it. 1.2 Debug introduction and operation process How to add breakpoints Select the line of code where you want to set the breakpoint by clicking the le ...

Day 5: object oriented inheritance final abstract class interface polymorphism 1. Inheritance: when multiple classes (subclasses, also known as derived classes) have the same attributes and methods, we extract these commonalities and put them into another class (parent class, also known as base class). This class is called parent class (base cl ...

JavaSE - Reflection - Annotation Learning objectives of this section: Understand the concept of annotation;Understand and master the use of annotations;Understand and master the Annotation interface and JDK meta Annotation;Understand and master the writing method of custom annotation;Understand and master how to use reflection to process anno ...

Chapter 16 reflection 16.1 class loading Class life cycle in memory: load – > use – > unload 16.1.1 loading process of class When a program actively uses a class, if the class has not been loaded into memory, the system will initialize the class through three steps: loading, connecting and initialization. If there is n ...

Chapter 5 methods and arrays 5.1. Method 5.1.1 method overview 01 concept 😀 Method: a code segment with a specific function. This code function is often used. Wrap it in curly braces and give it a name. Then take this name to represent this code. For example: Scanner Class nextInt() method, nextInt For the method name, enter an integer th ...

Annotation and reflection annotation What is annotation Annotation is a technology introduced by JDK5 Annotation is to explain the procedure What's the difference between annotation and annotation Annotations are explained to programs, and annotations are explained to people Format of annotation: Annotations exist in the code as "@ ...