How Can a Subordinate Function Affect the Execution Flow of its Parent Function in Go?

Returning from a Subordinate Function into a Parent Function

In programming, it is often necessary for a function to terminate the execution of its parent function. This can be achieved through various methods, depending on the programming language and the specific requirements of the program.

One such method is to use the return statement within the subordinate function. When a function encounters a return statement, it immediately exits the function and returns control to the calling function.

In the provided code example:

func apiEndpoint() {
    if false {
        apiResponse("error")
        // I want apiResponse() call to return (end execution) in parent func
        // so next apiResponse("all good") wont be executed
    }

    apiResponse("all good")
}

func apiResponse(message string) {
    // returns message to user via JSON
}

The intent is to terminate execution in the parent function apiEndpoint() upon calling the subordinate function apiResponse(). However, in Go, a function cannot directly control the execution flow of its caller. The caller is responsible for terminating execution.

One solution to this issue is to use an if-else statement within the parent function:

func apiEndpoint() {
    if someCondition {
        apiResponse("error")
    } else {
        apiResponse("all good")
    }
}

In this example, apiResponse("error") will be executed only if the someCondition is true. Otherwise, apiResponse("all good") will be executed.

Another solution is to use the return statement within the parent function:

func apiEndpoint() int {
    if someCondition {
        return apiResponse("error")
    }

    return apiResponse("all good")
}

func apiResponse(message string) int {
    return 1 // Return an int
}

In this example, the apiEndpoint() function returns the value of the apiResponse() function. If the someCondition is true, the apiEndpoint() function returns the error message. Otherwise, it returns the success message.

It is important to note that, in general, functions cannot control the execution of their callers. They can only return values or raise exceptions, which are then handled by the caller.

The above is the detailed content of How Can a Subordinate Function Affect the Execution Flow of its Parent Function in Go?. For more information, please follow other related articles on the PHP Chinese website!