Memory management revealed: Analysis of memory usage of formal parameters in Go language

Go language function parameters allocate memory on the stack and can be modified within the function, but do not affect the value of the actual parameters in the calling function. This is because the formal parameters are local variables and are isolated from the actual parameters.

Memory Management Revealed: Analysis of Memory Usage of Formal Parameters in Go Language

In Go language, the function parameters in memory are How is it distributed and used? By analyzing actual cases, this article will delve into the memory usage mechanism of formal parameters and help you understand memory management in Go programs.

Formal parameter memory allocation

In the Go language, function parameters allocate memory on the stack. The stack is a continuous memory area used to store the values ​​of local variables and formal parameters during function calls. When the function is called, the memory space of the formal parameters will be allocated, and the corresponding size of storage space will be allocated according to the formal parameter type.

Formal parameter memory usage

Formal parameters can be used like ordinary variables inside the function. The value of a formal parameter can be modified through direct assignment or pointer manipulation. However, modifying the formal parameter value will not affect the value of the actual parameter in the calling function, because the formal parameter is a local variable inside the function and is isolated from the actual parameters in the calling function.

Practical case

The following is a practical case for analyzing the memory usage of formal parameters:

func main() {
    var v int = 10
    f(&v)
    fmt.Println(v) // 输出：10
}

func f(p *int) {
    *p = 20
}

In this example, we define a functionf, which receives a pointer to type int as a formal parameter. In the main function main we create a int variable named v and pass it as an actual parameter to the f function .

Inside the f function, we dereference the formal parameter p and obtain the pointer to the original int variable. Then, we modify the value pointed to by that pointer and set it to 20.

It is worth noting that modifying the value of the formal parameter *p will not affect the value of the actual parameter v in the calling function. The reason is that p is a pointer to v, and the *p operation will modify the content pointed to by v, not v itself. Therefore, when the f function returns, the value of v is still 10.

Conclusion

By analyzing actual cases, we understand the allocation and use mechanism of Go language formal parameters in memory. Formal parameters are allocated in memory on the stack and can be modified inside the function, but will not affect the values ​​of the actual parameters in the calling function. By understanding the memory usage mechanism of formal parameters, we can write more robust and efficient Go programs.

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