我在运行以下代码时出现索引超出范围错误

Question

i having the following code to print the indexes of an array which contains similar values.

but on running this code getting panic: indexes out of range run time error

why i am getting this

package main

import "fmt"

func main()  {
    var numbers[] int = [] int {5,2,3,5,3}
    var copy_numbers[] int
    var count [5] int
    var i,j int
    copy(copy_numbers,numbers)
    for i=0;i<len(numbers);i++ {
        for j=0;j<len(numbers) ;j++  {
            if numbers[i]==numbers[j] {
                count[i]++;
            }
        }
    }
    fmt.Printf("%d",count)

    for i=0;i<len(numbers) ;i++  {
        fmt.Println("hello")
        if count[i]>1{
            for j=0;j<len(numbers) ;j++  {
                if numbers[i]==copy_numbers[j] {

                    fmt.Printf("%d",j)

                }
            }
            fmt.Println("")
        }
    }

fmt.Printf("%d",count)

}

Answer 1

copy_numbers is of size 0, just as you initialized it.

If I add the following before your first for loop:

fmt.Println(numbers)
fmt.Println(copy_numbers)

I get:

[5 2 3 5 3]
[]

the copy builtin copies up to the length of either argument, as mentioned in the docs:

Copy returns the number of elements copied, which will be the minimum of len(src) and len(dst).

You should initialize copy_numbers to be of the same length as numbers

  copy_numbers := make([]int, len(numbers))