• 186 key words and functions that must be mastered in learning programming (py form processing version)


    Indexes english chinese explain effect 1 abstract class abstract class Abstract classes cannot create objects. They are mainly used to create subclasses. Abstract classes in Java are defined using the abstract modifier. 2 abstract data type ADT Abstract data type Abstract classes cannot create objects. They are mainly used to create subclasses. Abstract classes in […]

  • Piziheng embedded: using memtester program to test SDRAM on i.mxrt1060-evk


    Hello everyone, I’m a ruffian Heng. I’m a serious technical ruffian. Today, ruffian Heng introduces to youUsing memtester program to test SDRAM on i.mxrt1060-evk。 We know that NXP i.mxrt1xxx series is the representative of high-performance MCU. For this monster with ultra-high dominant frequency (> = 500MHz), it’s a waste of its ability not to do […]

  • Application scenario analysis and code implementation of stack


    Stack A practical requirement of stack Please enter an expression formula:[7*2*2-5+1-5+3-3]Click calculate [as shown in the figure below] Excuse me: how does the bottom layer of the computer calculate to get the result? Note that it’s not a simple list of formulas, because we look at formula 722 – 5, but how does the computer […]

  • package


    Package can be arranged by using package. It contains two separate parts: package description (specification, header) and body (body). Both the package description and the package body are stored in the data dictionary. One obvious difference between packages and procedures and functions is that packages can only be stored in non local databases. To create […]

  • Python coroutine


      Before the coroutine, we understand the process and thread of Python. Here, let’s talk about the coroutine Instead, the subroutine switches itself There is no overhead of thread switching. Compared with multithreading, the more threads there are, the more obvious the performance advantage of coprocessor There is no need for multi-threaded locking mechanism, because […]

  • Programming with PLSQL


    Chapter 7  usePL/SQLprogramming Introduction to PL / SQL (procedure language & Structured Query Language) PL / SQL is a procedural extension of oracle on the standard SQL language. It allows embedded SQL statements, defines variables and constants, allows procedure language structures (conditional branch statements and loop statements) and allows exceptions to handle Oracle errors. It […]

  • Several common commands of window bat script


    Window bat script Control statement if for set Basic identification Comment command rem :: symbol echo Echo off / on off or show echo @ @Putting the character before the command turns off echo of the command Parameter usage %I represents the parameters in the batch file %0 for batch itself, full path with extension […]

  • Assembly language reading notes [transfer instructions]


    First, reference Assembly language – Wang Shuang Two, text The instructions that can modify IP, or both CS and IP are collectively referred to as transfer instructionsA transfer instruction is an instruction that can control the CPU to execute code somewhere in memory 2.2 call and RET instructions Call and RET instructions are both transfer […]

  • Perl subroutine sub


    I. definitionA subroutine is a separate piece of code that performs a special task. It can reduce duplicate code and make the program readable. In Perl, subroutines can appear anywhere in the program. The definition method is:  sub subroutine{     statements;   } II. CallThe call method is as follows:1. Use & call  &subname;   …   sub subname{     …   } 2. First […]

  • The Application of Perl Subprogram and the Importance of Variable Private (my) Declarations in Subprogram


    A conversion program that simply converts A into T in a DNA sequence does not use private variables in the first case. Copy codeThe code is as follows: #!/bin/perl# Here is a DNA sequence.DNA = ATTATATATAT; Here is our sequence.$result=A_to_T($DNA);  print “I changed all $DNA A to T, and the we get the result $result\n\n”;  […]

  • Introduction of Two Reference (Transfer) Ways of Parameters in Perl Neutron Program


    Here is an example: Copy codeThe code is as follows: use strict;# Here are two arraysmy @i =(‘1′,’2′,’3’);my @j =(‘a’,’b’,’c’); # Before processing, we print them out and see what they look like.print “In main program before calling subroutine:i=”.”@i\n”;print “In main program before calling subroutine:j=”.”@j\n”; # Then we deal with it through subroutines.reference_sub(@i,@j);print “In main […]

  • Perl Function (Subprogram) Learning Notes


    Definition of function A subroutine is a separate piece of code that reduces duplication and makes the program readable. In perl, subroutines can appear anywhere in the program. But they are usually placed at the beginning or end of the program. Copy codeThe code is as follows: sub subroutine{     statements; } At the beginning […]