Module initialization in Go - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the init function in Go?

The init function is used to initialize variables or state before the main program runs. It runs automatically when the package is loaded, without being called explicitly.

intermediate

How many init functions can a single Go package have?

A Go package can have multiple init functions, even within the same file or across different files in the package. All will run in the order the compiler decides.

beginner

When exactly are init functions executed in a Go program?

They run automatically after all package-level variables are initialized and before the main function starts.

beginner

Can you call an init function explicitly in Go code?

No, init functions cannot be called explicitly. They are called automatically by the Go runtime during program startup.

intermediate

What happens if multiple packages have init functions?

All init functions in imported packages run first, in the order of imports, before the init functions in the main package run.

What is the correct way to define an init function in Go?

A func init() { /* code */ }

B func initialize() { /* code */ }

C func Init() { /* code */ }

D func start() { /* code */ }

The init function must be named exactly init with no parameters or return values.

When does the init function run in a Go program?

A Before package-level variables are initialized

B After the <code>main</code> function runs

C Only when called explicitly

D After package-level variables are initialized and before <code>main</code>

The init function runs automatically after package variables are set and before main.

Can you have more than one init function in a single Go package?

A No, only one is allowed

B Yes, multiple are allowed

C Only one per file

D Only if they have different names

Multiple init functions can exist in the same package and will all run.

What happens if you try to call init() explicitly in your code?

A It is ignored

B It runs normally

C It causes a compile error

D It runs but only once

init functions cannot be called explicitly; attempting to do so causes a compile error.

If package A imports package B, when does package B's init run?

A Before package A's <code>init</code>

B After package A's <code>init</code>

C At the same time as package A's <code>init</code>

D Only if package B is used in <code>main</code>

Imported packages' init functions run before the importing package's init.

Explain the role and behavior of the init function in Go module initialization.

Think about what happens before your program starts running main.

Describe how Go handles multiple init functions across different packages during program startup.

Consider the sequence of package loading.