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

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。

其他回答

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

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。

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

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

对于带有range子句的语句:

带有“range”子句的“for”语句将遍历所有条目 数组、切片、字符串或映射,或在通道上接收的值。 对于每个条目,它将迭代值赋给相应的迭代 变量,然后执行块。

举个例子:

for index, element := range someSlice {
    // index is the index where we are
    // element is the element from someSlice for where we are
}

如果你不关心索引,你可以使用_:

for _, element := range someSlice {
    // element is the element from someSlice for where we are
}

下划线_是空白标识符,一个匿名占位符。