Go toolchain overview - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Go program using 'go run'?

Consider this Go program saved as main.go. What will be printed when you run go run main.go?

Go

package main
import "fmt"
func main() {
    fmt.Println("Hello, Go toolchain!")
}

A Hello, Go toolchain!

B main.go:1:1: expected 'package', found 'import'

C Error: cannot find package fmt

D No output

💡 Hint

Think about what go run does with a simple program that prints text.

The go run command compiles and runs the Go program. Since the program prints "Hello, Go toolchain!", that is the output.

🧠 Conceptual

intermediate

Which Go tool command compiles packages and dependencies?

Which go tool command compiles the packages and their dependencies but does not run the program?

A go test

B go install

C go build

D go run

💡 Hint

Think about the command that creates an executable without running it.

go build compiles the packages and dependencies and produces an executable file but does not run it.

❓ Predict Output

advanced

What error does this Go code produce when run with 'go run'?

What error message will this Go program produce when executed with go run?

Go

package main
func main() {
    var x int = "string"
}

A undefined: x

B no error, program runs successfully

C missing return statement

D cannot use "string" (type string) as type int in assignment

💡 Hint

Look at the variable type and the assigned value types.

The program tries to assign a string value to an int variable, which causes a type mismatch error.

🧠 Conceptual

advanced

What does 'go install' do differently than 'go build'?

Choose the correct statement about the difference between go install and go build.

A <code>go install</code> runs tests, <code>go build</code> does not.

B <code>go install</code> compiles and places the executable in the Go bin directory, <code>go build</code> only compiles locally.

C <code>go install</code> deletes source files after compiling, <code>go build</code> keeps them.

D <code>go install</code> only downloads dependencies, <code>go build</code> compiles code.

💡 Hint

Think about where the executable ends up after each command.

go install compiles the package and places the executable in the Go workspace bin directory, making it available globally. go build compiles locally without installing.

❓ Predict Output

expert

What is the output of this Go program using 'go run' with modules?

This Go program uses a module and imports fmt. What will be the output when running go run main.go inside a module-enabled directory?

Go

package main
import "fmt"
func main() {
    fmt.Println("Module enabled run")
}

A Module enabled run

B cannot find module for path fmt

C go: no Go files in .

D panic: runtime error

💡 Hint

Modules do not affect standard library imports like fmt.

The program prints the string because fmt is part of the standard library and modules do not block this import.