Detailed explanation of Golang formal parameter requirements: parameter type, number and order of parameters

Detailed explanation of Golang formal parameter requirements: parameter type, number and order of parameters

In Golang, the formal parameter definition of a function is very flexible and different types of parameters can be passed and a variable number of parameters. Formal parameters mainly include parameter type, parameter number and parameter order. The following will be explained in detail through specific code examples.

1. Parameter type
   In Golang, the formal parameters of a function can be basic types such as integer, string, Boolean, etc., or they can be customized structures, interfaces, etc. . Here is a simple example that demonstrates how to define different types of parameters:

package main

import "fmt"

func add(x, y int) int {
    return x + y
}

func concat(str1, str2 string) string {
    return str1 + str2
}

func main() {
    fmt.Println(add(5, 3))
    fmt.Println(concat("Hello", "World"))
}

In the above example, the add function accepts two integer parameters and the concat function accepts two string parameters, The functions of the two functions are implemented respectively, and the definition and use of different types of parameters are demonstrated.

2. Number of parameters
   In Golang, the number of formal parameters of a function does not need to be fixed, which is achieved by using a variable parameter function. Here is an example that demonstrates how to define a variable number of parameters:

package main

import "fmt"

func sum(nums ...int) int {
    total := 0
    for _, num := range nums {
        total += num
    }
    return total
}

func main() {
    fmt.Println(sum(1, 2, 3, 4, 5))
    fmt.Println(sum(10, 20, 30))
}

In the above example, the sum function uses the variadic syntax ...int to accept A variable number of integer parameters, the sum of which is calculated by traversing the parameter list.

3. Parameter order
   In Golang, the order of parameters of a function is very important. When calling a function, parameters must be passed in in the order in which the function is defined. The following is an example that demonstrates the importance of parameter order:

package main

import "fmt"

func multiply(x int, y int) int {
    return x * y
}

func main() {
    result := multiply(3, 4) // 正确的传参顺序
    fmt.Println(result)

    // result := multiply(4, 3) // 错误的传参顺序，编译报错
}

In the above example, the multiply function accepts two integer parameters, and the order of the parameters passed in when calling must be consistent with the function definition. The order is consistent, otherwise it will cause compilation errors.

Summary: Through the above examples, we explained in detail the formal parameter requirements in Golang, including parameter type, number of parameters and parameter order. Properly defining and using function parameters can make the program clearer and maintainable, and improve the readability and maintainability of the code.

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