What is the Purpose of Closures?

I really don't understand what the purpose of closures is. It seems to me that everything that can be written using closures, is just as easily written without. For example:


void main()
{
    int[] haystack = [345,15,457,9,56,123,456];
    int   needle = 123;
    bool needleTest(int n)
    {
        return n == needle;
    }
    printf(find(haystack, &needleTest));
}

Wouldn't this be better written as:


void main()
{
    int[] haystack = [345,15,457,9,56,123,456];
    int   needle = 123;
    foreach(int i : haystack)
    {
        if (i == needle)
        {
            printf(i);
        }
    }
}

Or at least defining the function outside of main() and referencing it inside? I just don't understand the benefit of closures.

>>22

import prague;
import std.stdio;

void main()
{
    int n = getPostNum(currentThread.mostRecentPost);
    void checkem()
    {
        if (to!string(n)[0] == to!string(n)[1])
        {
            currentThread.post("Nice dubs, bro!");
        }
    }
}