Important Characteristics of Go: Control

Controlling program flow

So far, we have seen Go variables, but how do we change the flow of a Go program based on the value of a variable or some other condition? Go supports the if/else and switch control structures. Both control structures can be found in most modern programming languages, so if a developer has already programmed in another programming language, they should already be familiar with if and switch. The if statements use no parenthesis for embedding the conditions that need to be examined because Go does not use parentheses in general. As expected, if has support for else and else if statements.

if statement

To demonstrate the use of if, let's use a very common pattern in Go that is used almost everywhere. This pattern says that if the value of an error variable as returned from a function is nil, then everything is OK with the function execution. Otherwise, there is an error condition somewhere that needs special care. This pattern is usually implemented as follows: