• Summary of const in c++


    1. Why use const Const in essence is not only a qualifier for variables, but also a qualifier for programmers. It reminds programmers that the value of variables qualified by const should not be changed, and when the compiler knows that the evaluation result of variables or expressions is constant, the compiler can also make […]

  • C++ foundation – Reference


    quote Basic use of references Function: alias variables Syntax: data type & alias = original name Quotation precautions Reference must be initialized Once initialized, the reference cannot be changed (an alias can only be initialized once: it can only be followed by an original name) Reference as function parameter When a function passes parameters, you […]

  • Class loading subsystem


    Virtual machine structure diagram Role of classloader subsystem The class loader subsystem is responsible for loading class files from the file system or the network. Class files have a specific file ID at the beginning of the file. Classloader is only responsible for loading class files. Whether it can run or not is decided by […]

  • C language – constants / variables


    catalogue constant variable Scope of variable Memory analysis of variables   constant Definition: describes some fixed data that cannot be changed Classification of constants: integer constants Binary octal number system hexadecimal Real constant Single precision float Double precision double character constant char string constant Enclosed in double quotation marks is a string constant #include int […]

  • [c programming] 02 – data type


    1、 Constants and variables 1. Constant const int Real constant Decimal decimal form Index form: \ (12.34e3\) (for \ (12.34\times 10^3\)) character constants Ordinary characters: expressed in single quotation marks. There can only be one character in single quotation marks. Character variables are stored in ASCII code Escape character Escape character Character value Output results […]

  • Use of iota in go


    Articles are constantly updated. Search “on wechat”Wuqinqiang’s late night canteen 」 introduce The go language does not actually have keywords that directly support enumeration. We usually passconst + iotaThe ability to implement enumeration. Someone has to ask, why do you have to use enumeration?stackoverflowThere is a highly praised answer on, as follows: You should always use […]

  • [JVM chapter] [composition of JVM]


    [Java] [JVM chapter] [composition of JVM] Code farmers’ notes from the second tier summarize knowledge points with their own understanding and learn from each other 1. JVM concept JVM is java virtual machine(Java virtual machine)JVM is a specification for computing devices. It is a fictitiouscomputer, which is realized by simulating various computer functions on a […]

  • Invariance of strings


    For a series of languages such as JS and c\. The same is true for the immutability of strings. You can see: The string of C can be changed.You can char str[] = “Foo”; str[0] = ‘G’ The contents of STR have indeed been changed. It can be proved by print. Print the contents and […]

  • C++ STL deque container


    1、 Foreword Deque is the abbreviation of double ended queue, also known as double ended queue container. Deque containers and vecotr containers have many similarities:① Deque containers are also good at adding or deleting elements at the end of the sequence (time complexity is O (1)), but not at adding or deleting elements in the […]

  • A jser dart learning log (2): variables and constants


    This article is the second in the series of “a jser’s dart learning log”. This series of articles mainly explore the similarities and differences between JS and dart, and smoothly transition to dart language while reviewing and consolidating JS.As the author is a beginner of dart, his understanding may be superficial and one-sided. If you […]

  • C++ STL deque iterator


    1、 Foreword The deque container iterator is of type random access iterator. 2、 Iterator member functions supported by deque function function begin() Returns a forward iterator pointing to the first element in the container; If it is a const type container, the function returns a constant forward iterator end() Returns a forward iterator pointing to […]

  • 2021-php interview questions – object oriented


    Series of articles: 2021-php interview question “database” related knowledge points interview summary 2021-php interview questions – object oriented 1. What is object-oriented? (answers with understanding)Object oriented is an idea based on process oriented, that is to say, object oriented is to realize functions through objects, encapsulate functions into objects, and let objects realize specific details. […]