Explore fun brain teasers to hone your logic, critical thinking, and problem-solving skills. Gain insights into Go and practice to avoid future mistakes.

go.tar.gz

Go lang

Who knew puzzles could be fun? Puzzles and brain teasers are a great way to practice your critical thinking and improve your logic and problem-solving skills. This course provides a basic understanding of Go. The teasers in this course will help you practice what you already know and help avoid future mistakes.

Go Brain Teasers

# Try it yourself ## 

Try executing the code below to see the result.


package main

import (
	"fmt"
	"time"
)

// Log is a log message
type Log struct {
	Message string
	time.Time
}

func main() {
	ts := time.Date(2009, 11, 10, 0, 0, 0, 0, time.UTC)
	log := Log{"Hello", ts}
	fmt.Printf("%v\n", log)
}



# Explanation ##
The `%v` verb will print all the struct fields.

package main

import (
	"fmt"
)

// Point is a 2D point
type Point struct {
	X int
	Y int
}

func main() {
	p := Point{1, 2}
	fmt.Printf("%v\n", p) // {1 2}
}


We’d expect the teaser code to print`{Hello 2009-11-10 00:00:00 +0000 UTC}`. 

However, it doesn’t,  due to the way the `Log` struct is defined. In **line 11** there is a field with no name, just a type. This is called **embedding**, and it means
that the `Log` type has all the methods and fields that `time.Time` has.

>**Note:** The `time.Time` defines a `String()` string method, which means it implements the [ `fmt.Stringer` interface. Also, `Log` embeds `time.Time` it also has a `String()` string method.  If 
the parameter passed to  `fmt.Printf` implements `fmt.Stringer`, `fmt.Printf` will use it instead of the default output.

If we change the definition in **line 11** for `time.Time`, we’ll see the expected output, which is `{Hello 2009-11-10 00:00:00 +0000 UTC}`.

We can also embed interfaces in Go. See the definition of `io.ReadWriter`, for
example:

Before We Begin

Puzzles

Wrapping Up

Puzzle 11 Explanation: Go Log

Try it yourself