Golang newbies' common problems revealed: from basics to advanced

To address common Golang problems faced by novices, this article provides the following solutions: data type conversion uses type(expression) syntax. Pointer operations use the & and * operators to modify the value of the pointed variable. Closures allow inner functions to access outer function scope variables. Goroutine implements concurrency and improves performance. An interface defines a set of methods that must be implemented by types that implement the interface.

Revelation of common problems faced by Golang novices: from basics to advanced

Preface

As a Golang novice , it is inevitable to encounter various difficult and complicated diseases in the process of learning and practice. This article will provide a detailed analysis of these difficult issues to help novices get started with Golang quickly.

1. Data type conversion

Data type conversion in Golang is mainly performed through the following syntax:

var variableType = type(expression)

Difficult cases:Convert int type to float64 type

var intVar = 10
var floatVar = float64(intVar)
fmt.Println(floatVar) // 输出：10.000000

2. Understanding and using pointers

A pointer is a variable pointing to another memory address, and the pointer can be modified through the pointer variable value.

var num = 10
var ptr *int = &num // & 取地址，* 取值
*ptr = 20 // 修改所指向的变量值
fmt.Println(num) // 输出：20

3. Understanding and application of closures

A closure refers to a function inside a function, which can access variables in the scope of the external function, even if the external The function has returned.

Practical case:

func outer() int {
    num := 10
    inner := func() int {
        return num + 1
    }
    return inner()
}

num := outer()
fmt.Println(num) // 输出：11

4. Usage of Goroutine

Goroutine is lightweight and lightweight in Go language Level threads can execute multiple tasks concurrently to improve program performance.

func sum(numbers []int) <-chan int {
    ch := make(chan int)
    go func() {
        sum := 0
        for _, n := range numbers {
            sum += n
        }
        ch <- sum
    }()
    return ch
}

func main() {
    numbers := []int{1, 2, 3, 4, 5}
    result := <-sum(numbers)
    fmt.Println(result) // 输出：15
}

5. Understanding and implementing interfaces

The interface defines a set of methods, and the type that implements the interface must implement these methods.

Practical case:

type Shape interface {
    Area() float64
    Perimeter() float64
}

type Rectangle struct {
    Width  float64
    Height float64
}

func (r Rectangle) Area() float64 {
    return r.Width * r.Height
}

func (r Rectangle) Perimeter() float64 {
    return 2 * (r.Width + r.Height)
}

rect := Rectangle{10, 5}
fmt.Println(rect.Area()) // 输出：50
fmt.Println(rect.Perimeter()) // 输出：30

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