本篇文章主要介紹 javascript 程式語言的基本語法

  • 變數
  • 陣列
  • 運算符號
  • if condition
  • for loop
  • for each
  • function
  • 常數物件

變數

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const a = 0
const b = 0.01
const c = "message"
const d = true
const e = null
const f = undefined

陣列

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const a = []
const a = [1, 2, 3]

運算符號

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a === b
a !== b
a > b
a >= b
a < b
a <= b
!a
a && b
a || b

if condition

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if (a > b) {
    ...
} else if (a < b) {
    ...
} else {
    ...
}

for loop

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for (let i = 0; i < 10; i++) {
    ...
}

for each

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for (const element of array){
    ...
}

function

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function Calculate() {
    ...
}

function Calculate(a) {
    ...
}

function Calculate(a) {
    ...
    return 0
}

常數物件

宣告

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const valueByKey = {}
const valueByKey = { "Id": 0 }

檢查存在

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const valueByKey = { "Id": 0 }
const key = "Id"
const isExisted = key in valueByKey

賦值

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const valueByKey = {}
const key = "Id"
const value = 0
valueByKey[key] = value

取值

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const valueByKey = { "Id": 0 }
const key = "Id"
const value = valueByKey[key]