话不多说，开学Go

package main
import (
    "fmt"
    "os"
)
func main() {
    /*
        light@city:~/server/go_learning/src/ch1$ go run hello.go guangcheng
        Hello World! guangcheng
    */
    if len(os.Args) > 1 {
        fmt.Println("Hello World!", os.Args[1])
    }
    os.Exit(0)
}

func TestXXX(t * testing.T){...}

package try_test
import "testing"
/*
编写测试程序
1.源码以_test结尾：xxx_test.go
2.测试方法名以Test开头：func TestXXX(t * testing.T){...}
*/
func TestFirst(t *testing.T) {
    t.Log("My first try!")
}

package fib

import (
    "testing"
)
//go test -v fib_test.go -timeout 30s
//`-v` 打印出日志到终端。`-timeout`测试限制时间。
var c int

func TestFibList(t *testing.T) {
    //初始化赋值，但没有使用这些变量，就会编译错误
    // var a int = 1
    // var b int = 1
    // var (
    //  a int = 1
    //  b     = 1 //类型推断
    // )
    a := 1
    b := 1
    c = 1 //全局变量赋值
    //单元测试中一般用Log
    // fmt.Print(a)
    t.Log(a)
    for i := 0; i < 5; i++ {
        // fmt.Print(" ", b)
        t.Log(" ", b)

        tmp := a
        a = b
        b = tmp + a
    }
    // fmt.Println()
}
func TestExchange(t *testing.T) {
    a := 1
    b := 2
    // tmp := a
    // a = b
    // b = tmp
    a, b = b, a //一句对多个变量赋值
    t.Log(a, b)
}

1.math.MaxInt64
2.math.MaxFloat64
3.math.MaxUint32

package type_test
import (
    "testing"
)
type MyInt int64
func TestImplicit(t *testing.T) {
    // var a int = 1
    var a int32 = 1
    var b int64
    //不支持隐式类型转换
    // b = a // cannot use a (type int) as type int64 in assignment
    // b = a //cannot use a (type int32) as type int64 in assignment
    //可以显式转换
    b = int64(a)
    var c MyInt
    //别名和原有类型也不能进行隐式转换
    // b = c //cannot use c (type MyInt) as type int64 in assignment
    t.Log(a, b, c)
    t.Log(a, b)
}
func TestPoint(t *testing.T) {
    a := 1
    aPtr := &a
    // aPtr += 1 不支持指针运算
    t.Log(a, aPtr)
    t.Logf("%T %T", a, aPtr) //int *int
}
//string是值类型，其默认的初始值为空字符串，而不是nil
func TestString(t *testing.T) {
    var s string
    t.Log("*" + s + "*") //**
    t.Log(len(s))        //0
}