Golang Beginner Snippets

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Conditional flow

if 1 == 2 {
 
}

Loop

For Loop

for i := 0; i < 10; i++ {
    fmt.Println(i)
}

While Loop

 
stack := []int{}
 
for len(stack) > 0 {
 
}

For-in

 
arr := []string{}
 
for index, item := range arr {
    // do something
}

Array & Map

Array Length

arr := []int{1, 2, 3}
fmt.Println(len(arr))

Array Push (Append)

arr := []int{1, 2, 3}
arr = append(arr, 4)

Assign Value to Map

m := make(map[string]int)
m["key"] = 1
fmt.Println(m)

Print Struct

log.Printf("%+v\n", res)
fmt.Printf("%+v\n", res)

Iterate over a Map

var employee = map[string]int{"Mark": 10, "Sandy": 20,
    "Rocky": 30, "Rajiv": 40, "Kate": 50}
for key, element := range employee {
    fmt.Println("Key:", key, "=>", "Element:", element)
}

Goroutine & Channel

Basic

func TestChannel(t *testing.T) {
	channel := make(chan string)
	defer close(channel)
 
	go func() {
		time.Sleep(1 * time.Second)
		channel <- "Hello channel"
		fmt.Println("Channel data sent")
	}()
 
	data := <-channel
 
	fmt.Println(data)
}

Output

Channel data sent
Hello channel

Channel In & Out

func OnlyIn(channel chan<- string) {
	channel <- "Only in"
}
 
func OnlyOut(channel <-chan string) {
	data := <-channel
 
	fmt.Println(data)
}

Buffered Channel

channel := make(chan string, 3)
 
defer close(channel)
 
channel <- "Hello 1"
channel <- "Hello 2"
channel <- "Hello 3"
channel <- "Hello 4"
 
fmt.Println("finish")

Output:

n/a

Error timeout to wait blocking process because there's no receiver on the channel. If the size is greater or equal 4, then there's no error.

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