在Go语言中有foreach结构吗? 我可以迭代一个片或数组使用for?
当前回答
下面是如何在Go中使用foreach的示例代码:
package main
import (
"fmt"
)
func main() {
arrayOne := [3]string{"Apple", "Mango", "Banana"}
for index,element := range arrayOne{
fmt.Println(index)
fmt.Println(element)
}
}
这是一个运行中的示例https://play.golang.org/p/LXptmH4X_0
其他回答
实际上,你可以对你的类型使用for range而不引用它的返回值:
arr := make([]uint8, 5)
i,j := 0,0
for range arr {
fmt.Println("Array Loop", i)
i++
}
for range "bytes" {
fmt.Println("String Loop", j)
j++
}
https://play.golang.org/p/XHrHLbJMEd
Go有一个类似foreach的语法。它支持数组/切片、映射和通道。
迭代数组或切片:
// index and value
for i, v := range slice {}
// index only
for i := range slice {}
// value only
for _, v := range slice {}
迭代一个地图:
// key and value
for key, value := range theMap {}
// key only
for key := range theMap {}
// value only
for _, value := range theMap {}
遍历一个通道:
for v := range theChan {}
遍历一个通道相当于从一个通道接收直到它关闭:
for {
v, ok := <-theChan
if !ok {
break
}
}
这可能是显而易见的,但你可以像这样内联数组:
package main
import (
"fmt"
)
func main() {
for _, element := range [3]string{"a", "b", "c"} {
fmt.Print(element)
}
}
输出:
abc
https://play.golang.org/p/gkKgF3y5nmt
下面是如何在Go中使用foreach的示例代码:
package main
import (
"fmt"
)
func main() {
arrayOne := [3]string{"Apple", "Mango", "Banana"}
for index,element := range arrayOne{
fmt.Println(index)
fmt.Println(element)
}
}
这是一个运行中的示例https://play.golang.org/p/LXptmH4X_0
我刚刚实现了这个库:https://github.com/jose78/go-collection。
这是一个如何使用Foreach循环的例子:
package main
import (
"fmt"
col "github.com/jose78/go-collection/collections"
)
type user struct {
name string
age int
id int
}
func main() {
newList := col.ListType{user{"Alvaro", 6, 1}, user{"Sofia", 3, 2}}
newList = append(newList, user{"Mon", 0, 3})
newList.Foreach(simpleLoop)
if err := newList.Foreach(simpleLoopWithError); err != nil{
fmt.Printf("This error >>> %v <<< was produced", err )
}
}
var simpleLoop col.FnForeachList = func(mapper interface{}, index int) {
fmt.Printf("%d.- item:%v\n", index, mapper)
}
var simpleLoopWithError col.FnForeachList = func(mapper interface{}, index int) {
if index > 1{
panic(fmt.Sprintf("Error produced with index == %d\n", index))
}
fmt.Printf("%d.- item:%v\n", index, mapper)
}
执行的结果应该是:
0.- item:{Alvaro 6 1}
1.- item:{Sofia 3 2}
2.- item:{Mon 0 3}
0.- item:{Alvaro 6 1}
1.- item:{Sofia 3 2}
Recovered in f Error produced with index == 2
ERROR: Error produced with index == 2
This error >>> Error produced with index == 2
<<< was produced
在操场上试试这段代码。