基本变量声明

Go 是一种静态类型语言，这意味着你通常必须声明正在使用的变量的类型。

// Basic variable declaration. Declares a variable of type specified on the right.
// The variable is initialized to the zero value of the respective type.
var x int
var s string
var p Person // Assuming type Person struct {}

// Assignment of a value to a variable
x = 3

// Short declaration using := infers the type
y := 4

u := int64(100)    // declare variable of type int64 and init with 100 
var u2 int64 = 100 // declare variable of type int64 and init with 100