golang error: 'invalid function call...' How to solve it?

Golang is a very popular programming language in recent years. It has the characteristics of high concurrency, efficiency and ease of use, and has received widespread attention and application. However, even developers with an in-depth knowledge of the language may encounter some problems, one of the more common problems is the "invalid function call..." error. This article will take you through the causes and solutions to this error.

1. What is "invalid function call..."?

In Golang, "invalid function call..." usually means that when a function is called, the function does not exist or does not match the provided parameters. This is usually caused by the following reasons:

• The function name is misspelled or the function does not exist
• The function call parameters do not match the function definition parameters
• The function definition The return value type does not match the actual return value type

2. How to solve "invalid function call..."?

When you encounter the "invalid function call..." error, you can take the following measures to solve it:

2.1 Check the spelling of the function name

When calling the function , make sure that the function name is spelled correctly, that is, consistent with the function definition name of the called function. Therefore, checking the spelling of the function name is the first thing to do when solving "invalid function call...".

For example:

package main
import (
    "fmt"
)
func main() {
    fmt.Prinltn("Hello, World!")
}

In the above example, fmt.Prinltn was mistakenly printed instead of fmt.Println, resulting in the "invalid function call..." error.

2.2 Check function parameters

Golang’s functions usually use pass-by-value or pass-by-reference. If the passed parameter type does not match the parameter type defined by the function, an "invalid function call..." error will be triggered. Therefore, you need to carefully check whether the function call parameters are consistent with the defined function parameters.

The sample code is as follows:

func main() {
    fmt.Println(add(1,2,3))
}
func add(a int, b int) int{
    return a + b
}

In the above code, the definition of the add function has only two parameters, but three parameters are passed in in the function call, resulting in An "invalid function call..." error occurred.

2.3 Check the return value type defined by the function

When the return value type defined by the function does not match the actual return value type, the "invalid function call..." error will also be triggered. Therefore, you may need to check the function definition or return value type to ensure correctness.

The sample code is as follows:

func main() {
    fmt.Println(get_name())
}
func get_name() string {
    return "John"
}

In the above code, the return value type defined by the get_name function is string, but not in the function call Use a variable to receive its return value. Therefore, the "invalid function call..." error occurs.

Summary

"invalid function call..." is one of the common errors in Golang, usually caused by misspelling of function name, mismatch of function call parameters and function definition parameters, and function definition return value Caused by reasons such as mismatch between type and actual return value type. When encountering this error, you need to carefully check the code to ensure that the function name, function parameters, and return value type defined by the function are consistent with actual use. When solving this problem, you can use debugging tools, such as Goland or VS Code, to help you find problems in the code and solve them.

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