What is React A JavaScript library Use component-based approach All individual entities become completely reusable and independent of each other Rendering the application is easy and not dependent on other components of the UI 2011 developed by Facebok developer Advantages:
Easy for UI testing High readability Both client-side and server-side Easy understanding and boost efficiency Disadvantages:
Writing code is compliciated Hard to cope its syntaxes and methods React is a simple library, not a complete framework, so it calls for dependency Angular vs React Important feature of React React makes use of a single-direction data flow model It deals with complete server-side data processing and handling React uses Virtual DOM that has many advantages What is DOM (Document object model) When load HTML file, DOM is the representation of the same HTML document in a different format for Javascript access
Class Blue print of the objects
Object An object is an instance of a class (Class -> blueprint, Object -> house)
Constructor Initialize the state of an object
Destructor Automatically called at the end of lifetime of an object Free up the acuired resources
Is-A Relationship Inheritance (Parent-Child)
class Apple extends Fruit { } Foo is-a Bar:
public class Foo extends Bar{} Has-A Relationship Composition: Creating instances which have references to other objects (Objects depend on each other)
How data are ACTUALLY sotred? In a nutshell: All data are stored as 1’s and 0’s, 1 and 0 are represented by high/low voltage of transistors.
Brief Introduction Data are stored in bits, neither binary nor hex. They are both representations of data.
Computer only identifies voltage levels. There will be some voltage for 1 (high) and some lower voltage for 0 (low). When ever high voltage is passed its 1 and other one is 0.
So..What’s the Difference? A modem is your gateway to the internet—a cable, fiber optic, or telephone line comes through your neighborhood, to your house, and connects to your modem. The modem translates the digital 1s and 0s from your computer into analog information for the cable or telephone wire to carry out to the world, and translates incoming analog signals in the same way. This is called modulation and demodulation, respectively, and it’s where the “mo-dem” gets its name.
Executable files (.exe) An executable file is a type of computer file that runs a program when it is opened. This means it executes code or a series of instructions contained in the file. The two primary types of executable files are 1) compiled programs and 2) scripts. Executable files are not necessarily binary, for example a Python script in text form can be made executable on Unix systems by writing a shebang line #!
About code Sometimes I got confused by some concepts, such as machine code and object code. Here’s a collection of “code” definitions
Source code: (.c file) Any collection of code, with or without comments, written using a human-readable programming language, usually as plain text.
Assembly code (.s file) is plain-text and (somewhat) human read-able source code that mostly has a direct 1:1 analog with machine instructions. This is accomplished using mnemonics for the actual instructions, registers, or other resources.
