constdelta =1// untyped constant, default type is int varnumint64 num += delta 如果我们把const换成var,代码无法编译,会爆出这种错误:invalid operation: num + delta (mismatched types int64 and int)。 但为什么常量可以呢?这就是Representability或者说类型自动匹配在捣鬼。 按照官方的解释:如果一个无类型...
packagemainimport("fmt""unsafe")funcmain(){// 超出了int8存储范围,编译报错: cannot use 222 (untyped int constant) as int8 value in variable declaration (overflows)// var n1 int8 = 222// fmt.Println(n1)// 超出了uint8的存储范围,编译报错: cannot use -22 (untyped int constant) as uint...
当你声明一个常量并且其值超出了uint64的最大值(即18446744073709551615),Go 会将其类型推断为未指定大小的整数类型,这种类型在 Go 中被称为“untyped constant”(无类型常量)。 无类型常量具有特殊的性质,它们不绑定于具体的整型大小(如int,uint,int64等),而是可以根据上下文进行类型转换。这意味着,当这个无类型常...
// var num int8 = 128 cannot use 128 (untyped int constant) as int8 value in variable declaration (overflows) var num1 uint8 = 128 fmt.Print(num1) var num2 uint16 = 228 fmt.Print(num2) var num3 uint32 = 328 fmt.Print(num3) var num4 uint64 = 428 fmt.Print(num4) var nu...
.\test.go:11:9: cannot use 1 (untyped int constant) as string value in assignment > Elapsed: 0.561s > Result: Error 1. 2. 3. 4. 5. 最后,声明了变量就需要使用,如果不用,那么声明的意义在哪儿呢? func main() { var a string = "abc" ...
constdelta =1// untyped constant, default type is intvarnumint64num += delta AI代码助手复制代码 如果我们把const换成var,代码无法编译,会爆出这种错误:invalid operation: num + delta (mismatched types int64 and int)。 但为什么常量可以呢?这就是Representability或者说类型自动匹配在捣鬼。
// 编译错误:invalid array length 0 (untyped int constant) varemptyArr [0]int // 但允许零长度切片 emptySlice := []int{} 三、操作行为的对比分析 扩容机制是切片的核心特性。当append操作超过cap时,会触发扩容: 复制 s :=make([]int,2,3) ...
对比变量(variable)用于存储可变的数据,常量(constant)用于存储固定不变的数据,比如: 与变量声明类似,声明变量用关键词,声明常量用关键词 在变量声明各种形式的基础上,将关键词换成关键词,即可声明常量: 在Golang中,有两种常量,分别是: 未定类常量(Untyped Constant) ...
iota Constant In the Go programming language,iotais an untyped int type of value that is a predeclared identifier (represents the untyped integer ordinal number of the currentconstspecification in a (usually parenthesized)constdeclaration). It is zero-indexed. ...
package foo import "fmt" func Foo() { const foo = 0xff000000 fmt.Printf("%v", foo) } $ gomobile bind -target android . foo.go:7:19: cannot use foo (untyped int constant 4278190080) as int value in argument to fmt.Printf (overflows) ...