Test map delete while iterating

package main

import (
    "fmt"
    "encoding/json"
)

func main() {
    fmt.Println("Hello, playground")
    tm := make(map[int]int)

    for i := 0 ; i < 10 ; i++ {
        tm[i] = i ;
    }

    a, _ := json.Marshal(tm)
    fmt.Println(string(a))

    finalMap := []int{}
    v := 0
    _ = v

    arr := []int{5, 6, 7, 8 , 9, 4, 32 , 2, 11}
    for _, arrVal := range arr{
        if val, ok := tm[arrVal] ; ok {
            finalMap = append(finalMap, val)
            delete(tm, arrVal)
        }

    }

    b, _ := json.Marshal(tm)
    fmt.Println(string(b))

    for _, key := range tm {
        finalMap = append(finalMap, tm[key])
        delete(tm, key)
    }

    c, _ := json.Marshal(finalMap)
    fmt.Println(string(c))
}