英文:
len method undefined
问题
我一直在阅读[golang-book]: http://www.golang-book.com，并且在阅读过程中完成了练习。在第6章中，有一个练习必须找到未排序列表[x]中的最小元素。
我有以下代码，但不知道为什么方法length (len) 在第14行给我一个错误：x.len未定义（类型[]int没有字段或方法len）
package main
import "fmt"
func main() {
x := []int{
48, 96, 86, 68,
57, 82, 63, 70,
37, 34, 83, 27,
19, 97, 9, 17,
}
small := x[0]
for i := 1; i < x.len(); i++ {
if x[i] < small {
fmt.Println(x[i])
}
}
}
我使用的逻辑是通过谷歌搜索得到的，所以可能数组上没有len方法？非常感谢任何帮助。
英文:
I've been reading the [golang-book]: http://www.golang-book.com and completing the excercises as I go along. In Chapter 6, there is an exercise that must find the smallest element in an unsorted list[x].
I have the following code but somehow I don't know why the method length (len) gives me an error on line 14: x.len undefined (type []int has no field or method len)
package main
import "fmt"
func main() {
x := []int{
48, 96, 86, 68,
57, 82, 63, 70,
37, 34, 83, 27,
19, 97, 9, 17,
}
small := x[0]
for i := 1; i < x.len(); i++ {
if x[i] < small {
fmt.Println(x[i])
}
}
}
The logic I used was Googled so perhaps there is no len method on arrays? Any help is greatly appreciated.
答案1
得分: 8
数组和切片没有len()方法。len()函数是语言内置的。
所以你的代码
for i := 1; i < x.len(); i++ {
应该改为
for i := 1; i < len(x); i++ {
这是一个在<a href="http://play.golang.org/p/hVetB2_acU">playground</a>上工作的版本。
package main
import "fmt"
func main(){
x := []int{
48,96,86,68,
57,82,63,70,
37,34,83,27,
19,97, 9,17,
}
small := x[0]
for i := 1; i < len(x); i++ {
if x[i] < small {
fmt.Println(x[i]);
}
}
}
英文:
Arrays and slices do not have a len() method. The len() function is a language built-in.
So your code
for i := 1; i < x.len(); i++ {
Should be
for i := 1; i < len(x); i++ {
Here is a working version in <a href="http://play.golang.org/p/hVetB2_acU">the playground</a>.
package main
import "fmt"
func main(){
x := []int{
48,96,86,68,
57,82,63,70,
37,34,83,27,
19,97, 9,17,
}
small := x[0]
for i := 1; i < len(x); i++ {
if x[i] < small {
fmt.Println(x[i]);
}
}
}
答案2
得分: 4
len()不是切片的方法，它是一个全局函数。你想要说的是len(x)。
package main
import "fmt"
func main() {
x := []int{
48, 96, 86, 68,
57, 82, 63, 70,
37, 34, 83, 27,
19, 97, 9, 17,
}
small := x[0]
for i := 1; i < len(x); i++ {
if x[i] < small {
fmt.Println(x[i])
}
}
}
英文:
len() isn't a method of a slice. It's a global function. You want to say len(x).
package main
import "fmt"
func main() {
x := []int{
48, 96, 86, 68,
57, 82, 63, 70,
37, 34, 83, 27,
19, 97, 9, 17,
}
small := x[0]
for i := 1; i < len(x); i++ {
if x[i] < small {
fmt.Println(x[i])
}
}
}
答案3
得分: 1
实际上，数组和切片类型可以有一个len()方法，就像这样：
http://play.golang.org/p/CkU4LJZgUb
package main
import "fmt"
type SliceType []int
func (s SliceType) len() int {
return len(s)
}
func main() {
s := SliceType{1, 2, 3, 4, 5, 6, 7, 8, 9}
for i := 0; i < s.len(); i++ {
fmt.Println(s[i])
}
}
你找到的代码可能是container/list或container/ring的实现，它们都指定了一个Len()方法。
然而，原始切片和数组没有任何附加的方法，你必须使用内置函数len()。
英文:
In fact, array- and slice-types can have a len() method, like this:
http://play.golang.org/p/CkU4LJZgUb
package main
import "fmt"
type SliceType []int
func (s SliceType) len() int {
return len(s)
}
func main() {
s := SliceType{1, 2, 3, 4, 5, 6, 7, 8, 9}
for i := 0; i < s.len(); i++ {
fmt.Println(s[i])
}
}
The code you found is probably an implementation of container/list or container/ring, both of which specify a Len() method.
Primitive slices and arrays, though, don't have any methods attached to them and you must use the built-in function len().
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