Javascript Notepad by Duy Nguyễn

Lesson 1_ Introduction

duy011148 — 2023-03-25 01:50:01 UTC

// function of alert() --> To create a small notification on top of the websitealert('Hello, World!')
// function of var x = str/int --> To attach a string/integer value for a specific variationvar x = 'My name is JavaScript'var y = 'Nice to meet you!'alert(x)alert(y)
// function of document.write('text here') --> To write characters on the websitedocument.write("Welcome to my Website!","
")document.write("There's nothing so special about it tho")
// function of console.log() --> To write texts in the console page (console is in Inspection Page)// different variations of console.log --> console.warn() ; console.error()console.log("Hello, User!")console.warn("An elaborate precaution :)")console.error("An error has occured :(")

Lesson 2_ Object Determination

duy011148 — 2023-03-25 01:51:01 UTC

// Primitive data type - complex // Primitive: number(number), string (string of text), boolean (true // false - true false), undefined (undefined variable), null (no value) any value) // Complex: Array, Object, Function, RegEx, Date, etc. // Complex variable: Array - Group of similar values // Object - Represents an object / accessible objects access // Object as key - value // eg: ob1: 'hi' // Array can be used as var MyArray =

Lesson 3_ Mathemetic Operator

duy011148 — 2023-03-25 01:52:17 UTC

There are two main types of operators used in JS:
+) Comparison operator: < (less than); > (greater than); = (equal) ; <= (less than or equal to)
; >= (greater than or equal to); == (equivalence comparison) - same in character; = (assign value to x); != (different comparison)
; === (absolute comparison) - Compares the same character and data type

+) Logical operator (true/false comparison):
The computer will give priority to receive the first value first

If the value 1 is true, then get all without looking at b and c
If the value 1 is wrong, the other values will be looked at

&& - AND (and)
[ returns True when both gtris are True
  For example: a && b with a = True, b = False -> True
      a && b with a = True, b = True -> True
      a && b with a = False, b = False -> False


!gtri
[ Returns the opposite gtri of a
  For example: !a with a is True -> False
      !b where b is False -> True

+) operator if (compare conditions):
Statement: if (condition) { -> Remember to use curly brackets
| command line
} -> Close brackets
VD:
var a = 1
var b = 2
if (a == b) { -> Condition 1
| console.log("True")
}else if (a != b) { -> Create condition 2
| console.log("True-2")
}
else { -> Remaining condition
| console.log("False")
}

Return Value --> "True-2"

Lesson 4_ Function

duy011148 — 2023-03-25 01:52:46 UTC

// The function command in Javascript is used with the purpose of creating a defined integrated command which consists of many other small commands inside and leads to a narrative of events when being executed (Basically the same as the def() command in Python)

The formula of the function() command can be interpreted down below:
function nameFunction (attached value, attached value 2) {
        list of other commands
}
*attached value - a value that is attached inside of the function command and takes part as a factor of the command

*nameFunction - name of the Function (can be manually changed)

// e.x: 
function Addition_Math (value1, value2) {
      add_value = value1 + value2
      document.writeIn(value3)
}
Addition_Math(1,2)

Returned value:
3

Additional commands: eval()
// Function of eval(): It looks cool (especially in Mathematic commands)

Lesson 5_ Database

duy011148 — 2023-06-10 02:44:31 UTC

Database là cơ sở nền tảng lưu trữ và cung cấp dữ liệu, có thể dễ dàng truy cập, truy xuất và cập nhật thông tin. Về mặt lập trình viên, Database giúp cho các lập trình viên có thể quản lý dữ liệu dễ dàng và tổ chức hơn.

Heroku là nền tảng đám mây cho phép các lập trình viên triển khai, xây dựng, quản lý (điều hành và vận hành máy chủ phần mềm và phần cứng) và mở rộng ứng dựng (PPaS - Platform as a service). Heroku là một nền tảng rất linh hoạt và dễ sử dụng.