Go language learning data types

Data Types ### Go language learning

Data type conversion

1.Go language does not allow implicit type conversions (display conversion can)
2. aliases and original type can not be implicit type conversion

example:

func TestImplicit(t *testing.T){
    var a int  = 1
    var b int64
    //b = a           //a和b数据类型不一致，隐式转换就失败
    b = int64(a)      //显式转换才可以
    t.Log(a, b)
}

Pointer types

1 does not support pointer arithmetic

example:

//指针不能运算
func TestPoint(t *testing.T){
    a := 1
    aPtr := &a   //指针就是取a的地址
    //aPtr = aPtr + 1  错误，指针不能进行运算
    t.Log(a, aPtr)
}

2.string are value types, the default is an empty string, not nil

example:

//空字符串初始值为string,并不是nil
func TestString(t *testing.T){
    var s string  //定义一个字符串类型的值s
    t.Log("*"+s+"*")  //看这值是否为 **
    t.Log(len(s))  //查看s的长度，为0
}