declare a function with single parameter in Go

func functionName(parameter1 type) returnType {
    // Code body
}

This is a simple example of declaring a function with a single parameter in Go. The function keyword is used to start the declaration of the function. After that, the function name and parenthesis are used to contain any parameter value. The type of the parameter needs to be provided. After that, the return type of the function is specified. Lastly, the code body of the function is written inside curly brackets.

The function will accept the parameter value of the type specified and execute the code body, then use a return statement to exit the function and return the value of the return type. The return type can be omitted if nothing needs to be returned.