Do you know some details hidden in Go language?

Recently, more and more programmers have begun to learn and use Go language. The Go language has the characteristics of efficiency, simplicity, and concurrency, and is widely used in cloud computing, big data, distributed systems and other fields. However, many people are unaware of some hidden details of the Go language, which this article will reveal to you.

1. The difference between arrays and slices

In the Go language, an array is a set of fixed-size element sequences, while a slice is a fragment reference to the array. You can Dynamically increase or decrease its length. While both can access their elements via indexes, the usage and syntax are quite different.

For example, the length of an array is fixed and cannot be changed, and is always copied when passed, while a slice can increase or decrease the length as needed, and can also be passed as a parameter. No need to copy the entire array.

2. Usage of defer keyword

The defer keyword in Go language can be used to perform some cleanup work before the function returns, such as closing files, releasing memory, etc. It can be used anywhere in a function and will be executed automatically when the function returns.

For example, the following code can ensure that the file is closed after the function is executed:

func readFromFile(filename string) {
    file, err := os.Open(filename)
    if err != nil {
        panic(err)
    }
    defer file.Close()

    // do something with file
}

In the above code, we use the defer keyword to delay the execution of file.Close(), so that The file is guaranteed to be closed when the function returns, without the need to manually close the file at each return path of the function.

3. The difference between double quotes and backticks

In Go language, strings can be represented by double quotes or backticks. The difference lies in the double quotes in the string. Escape characters can be included, but no escaping is required in backtick strings.

For example, an escape character is required to represent a newline character in a double-quote string:

str := "hello\nworld"

. In a backtick string, a newline character can be used directly:

str := `hello
world`

In addition, backtick strings can span multiple lines without using plus signs or other concatenation characters.

4. Use of empty interface

The empty interface interface{} in Go language can represent any type, so it can be used without knowing the specific type. It is often used to implement functions such as generic types and type conversions.

For example, the following function can accept parameters of any type:

func printValue(v interface{}) {
    fmt.Println(v)
}

Additionally, an empty interface can be converted to a concrete type through type assertion:

func getTypeName(v interface{}) string {
    switch v.(type) {
    case int:
        return "int"
    case string:
        return "string"
    default:
        return "unknown"
    }
}

In the above code , we use switch and type to determine the specific type of the empty interface v, and return the corresponding type name.

5. Use of go keyword

The go keyword in Go language can be used to start a new coroutine or goroutine, which can make the program execute concurrently and improve Program performance and efficiency.

For example, the following code can start a new coroutine to execute the doSomething function:

go doSomething()

During concurrent execution, you need to pay attention to issues such as memory synchronization and resource management, otherwise data competition will occur. and deadlock issues.

Summary

The above are some hidden details in the Go language, which can help you better understand and use the Go language and improve the efficiency and performance of the program. In actual development, it is necessary to select appropriate data types and syntax according to the specific situation, and at the same time, it is necessary to follow the design philosophy and specifications of the Go language to ensure the robustness and maintainability of the program.

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