You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: main.go
    path of file: ./repos/learning/golang/source_code/Go语言核心编程代码/chapter05/exec/exec01
    
    the code of the file until where you have to start completion: package main
import (
	"fmt" 
)

func main() {
	//编写程序，声明2个int32型变量并赋值。判断两数之和，如果大于等于50，打印“hello wo
    
func main() {
	//编写程序，声明2个int32型变量并赋值。判断两数之和，如果大于等于50，打印“hello world!”

	//分析
	//1. 变量 
	//2. 单分支

	var n1 int32 = 10
	var n2 int32 = 50
	if n1 + n2 >= 50 {
		fmt.Println("hello,world")
	}

	//编写程序，声明2个float64型变量并赋值。判断第一个数大于10.0，
	//且第2个数小于20.0，打印两数之和

	var n3 float64 = 11.0
	var n4 float64 = 17.0
	if n3 > 10.0 && n4 < 20.0 {
		fmt.Println("和=", (n3 + n4) )
	}

	//7)【选作】定义两个变量int32，判断二者的和，是否能被3又能被5整除，打印提示信息

	var num1 int32 = 10
	var num2 int32 = 5
	if (num1 + num2) % 3 == 0 &&  (num1 + num2) % 5 == 0 {
		fmt.Println("能被3又能被5整除")
	}

	//8)判断一个年份是否是闰年，闰年的条件是符合下面二者之一：
	//(1)年份能被4整除，但不能被100整除；(2)能被400整除
	var year int = 2019
	if (year % 4 == 0 && year % 100 !=0) || year % 400 == 0 {
		fmt.Println(year, "是润年~")
	}

	
}