從測試中學習 Go 語言 (變數、條件判斷篇) - nofear195's blog

nofear195 included in Go

2024-02-17 2024-02-18 About 300 words One minute - views - comments

Contents

Types

Base Types
- int
- float64 : 十進制的雙精度浮點數
- string
- bool : true or false
Composite Types (複合類型)
- slice
- map
- struct
Pointer Types
- pointer : *T
Interface Types
- interface{}
Function Types
- func
Channel Types
- chan T

Variable Declaration

var

宣告有明確類型的變數
變數值可改變
可以使用簡短宣告的方式，一次宣告變數並為其賦值：:=

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var age string
age = 5
// 等同於使用 := 
age := 5

const

宣告不可改變值的變數
可用 () ㄧ次性包裹所有需定義為 const 的變數

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const pi = 3.14

const (
  french  = "French"
  spanish = "Spanish"
)

type

用於宣告自定義的類型或別名

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type Bitcoin int

type Wallet struct {
 balance Bitcoin
}

type Stringer interface {
 String() string
}

Conditionals

if-else

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num := 10
if num > 0 {
    fmt.Println("Number is positive")
} else if num == 0 {
    fmt.Println("Number is zero")
} else {
    fmt.Println("Number is negative")
}

// Example of if statement within initialization
if num := 15; num > 10 {
    fmt.Println("Number is greater than 10")
}

switch-case

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fruit := "apple"
switch fruit {
case "apple":
    fmt.Println("It's an apple")
case "banana":
    fmt.Println("It's a banana")
default:
    fmt.Println("It's something else")
}

Reference

https://quii.gitbook.io/learn-go-with-tests/