golang 缺少逗号报错问题

　　一个逗号引发的语法报错问题：syntax error: unexpected newline, expecting comma or }或者missing ',' before newline in composite literal

　　代码如下：

　　

func main() {
	boxes := Boxlist{
		Box{4, 4, 4, RED},
		Box{5, 5, 5, YELLOW},
		Box{6, 6, 6, BLACK},
		Box{10, 10, 10, BLUE},
		Box{8, 8, 8, WHITE}, // 此处逗号不可省略   115:19: missing ',' before newline in composite literal
	}

func main() {
	a := map[string]int{
		"golang": 2,
		"python": 1,
		"java":   3, // syntax error: unexpected newline, expecting comma or }
	}
	Println(a)
}