Which "out. Close" is Better?

[Hamed_Mostafaei (Ήαϻe̸d̨ M)]

Hi there

Which “out. Close” good performance for language? (as u know “defer” not good in for)

1 .

func SaveAvatar() string{
	var size [6][2]uint
	    size[0] = [2]uint{75, 30}
	    size[1] = [2]uint{100, 40}

	for _, v := range size {
		out, err := os.Create("pic/ava/" + "u" + "_" +
			"150000" + "_" + "123" + "_" + strconv.Itoa(int(v[0])) + "." +"JPG")
		if err != nil {
			return "R_FAILED"
		}
		//jpeg.Encode(out, Avatar, nil)

		err =os.Remove("Av" + "_" + strconv.Itoa(int(v[0])) + "." + "JPG")
		if err != nil {
			return "R_FAILED"
		}
		out.Close()
	}
	return "R_Succ"
}

func SaveAvatar() string{
	var size [6][2]uint
	    size[0] = [2]uint{75, 30}
	    size[1] = [2]uint{100, 40}

	for _, v := range size {
		out, err := os.Create("pic/ava/" + "u" + "_" +
			"150000" + "_" + "123" + "_" + strconv.Itoa(int(v[0])) + "." +"JPG")
		if err != nil {
		out.Close()
			return "R_FAILED"
		}
		//jpeg.Encode(out, Avatar, nil)

		err =os.Remove("Av" + "_" + strconv.Itoa(int(v[0])) + "." + "JPG")
		if err != nil {
		out.Close()
			return "R_FAILED"
		}
		out.Close()
	}
	return "R_Succ"
}

here is playGround :

https://play.golang.org/p/49u1nJYi8xU

Thanks in Advance.

[johandalabacka (Johan Dahl)]

See this discussion. Wrapping it in an anonymous function could be a solution

`defer` in the loop - what will be better?

[jayts]

Hi Hamed,

Two things:

1. If the open (or create) fails, then there is no file to close. You do not have to call out.Close() because out is nil.

2. You just need to close the file after you are done using it. So put your os.Close() immediately after the jpeg.Encode().

Try this: https://play.golang.org/p/8W9ezx4UBTf

[johandalabacka (Johan Dahl)]

out, err := os.Create("pic/ava/" + "u" + "_" + "150000" + "_" + "123" + "_" + strconv.Itoa(int(v[0])) + "." +"JPG")

Could be rewritten as

out, err := os.Create(fmt.Sprintf("pic/ava/u150000_123_%s.JPG", v[0]))

which is a little shorter and it is easier to see what path is used for os.Create. Same thing with the argument to os.Unlink