Analysis of reference passing mechanism in Go language

The variable passing mechanism in Go language is divided into value passing and reference passing. Passing by value creates a copy of the new variable, while passing by reference directly operates on the memory address of the original variable. Specifically: value transfer: the default mechanism, changes to the original variable do not affect the new variable. Pass by reference: By using pointers, changes to the new variable are reflected in the original variable. Practical case: Using pointers as function parameters, the value of the variable can be modified outside the function. Note: Modifying reference variables will affect all variables pointing to the same memory address. Make sure the pointer points to a valid address and avoid using value passing and reference passing at the same time.

Analysis of reference passing mechanism in Go language

In Go language, variables can be passed by value or by reference. Passing by value creates a new variable that has the same value as the original variable, but they exist independently. Passing by reference will directly operate the memory address of the original variable, and changes to the new variable will also be reflected in the original variable.

Value passing

Value passing is the default delivery mechanism in the Go language. In value transfer, the new variable will get a copy of the original variable, and any changes to the original variable will not affect the new variable.

package main

import "fmt"

func main() {
    x := 10
    y := x // y将会得到x的副本
    x++      // 更改x不会影响y
    fmt.Println(x, y) // 输出：11 10
}

Passing by reference

In the Go language, passing by reference can be achieved by using pointers. Pointers store the address of a variable in memory, not the value of the variable.

package main

import "fmt"

func main() {
    x := 10
    y := &x // y指向x的内存地址
    *y++      // 更改*y会更改x的值
    fmt.Println(x, *y) // 输出：11 11
}

In the above example, *y will dereference the pointer and obtain the variable pointed to by the pointer. The operation on *y is actually the modification of x.

Practical Case

In the Go language, reference passing is usually used when external variables of a function need to be modified. For example, using a pointer as a function parameter can change the value of a variable outside the function:

package main

import "fmt"

func increment(p *int) {
    *p++ // 解引用指针并递增其值
}

func main() {
    x := 10
    increment(&x) // 将x的地址作为参数传递给函数
    fmt.Println(x) // 输出：11
}

Notes

When using reference transfer, you need to pay attention to the following:

• Modifications to a reference variable affect all variables pointing to the same memory address.
• Ensure that the pointer does not point to an invalid memory address (nil) when using reference variables.
• Avoid using both pass-by-value and pass-by-reference to modify the same variable, as this may cause unpredictable behavior.

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