What are the common mistakes in Go language?

Go language is a fast, concise, and safe programming language. Its design goal is to improve programming efficiency and reduce system load. However, even the best programming languages ​​are not immune to common errors. In this article, we will explore some common mistakes in Go language and how to avoid them.

1. Null pointer reference

The Go language does not support null pointer reference. Attempting to access a null pointer results in a runtime error. To avoid this error, we need to always check if a pointer is null before using it. The sample code is as follows:

var p *int
if p != nil {
    fmt.Println(*p)
}

2. Array out-of-bounds access

For arrays, the Go language does not check whether the array index is out of bounds. Therefore, accessing an element that does not exist in the array may cause the program to crash. To avoid this situation, we need to ensure that the index value is within the range of the array length. The sample code is as follows:

var a [5]int
if i >= 0 && i < len(a) {
    fmt.Println(a[i])
}

3. Passing of function parameters

In the Go language, function parameters are passed by value. This means that when we pass a structure or array as a parameter, what is actually passed is a copy of the structure or array. If we need to modify the original data, we must pass a pointer to the original data. The sample code is as follows:

func modifySlice(a []int) {
    a[0] = 100
}
func main() {
    s := []int{1, 2, 3}
    modifySlice(s)
    fmt.Println(s[0]) // 输出 100
}

4. Uninitialized variable

Uninitialized variable contains an undefined value. If we try to use an uninitialized variable, a compilation error will be thrown. Therefore, we should always initialize a variable before using it. The sample code is as follows:

var s string
s = "hello"
fmt.Println(s)

5. Concurrent access to shared variables

In multi-threaded programming, shared variables may cause race conditions. The Go language provides mechanisms such as pipes and mutex locks to avoid multi-thread conflicts. Therefore, when we write concurrent programs, we should always consider protecting shared variables. The sample code is as follows:

var count int
mutex := sync.Mutex{}
func increment() {
    mutex.Lock()
    count++
    mutex.Unlock()
}
func main() {
    for i := 0; i < 1000; i++ {
        go increment()
    }
    time.Sleep(time.Second)
    fmt.Println(count)
}

In short, common errors in the Go language include null pointer references, array out-of-bounds access, function parameter passing, uninitialized variables, and concurrent access to shared variables. To avoid these common mistakes, we need to think carefully about the problem before writing code and use the correct method to deal with it.

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