Working of scanf under for loop

I have a question about working of for loop in C. Please have a look at the following code:

#include<stdio.h>

void main()
{
    int ar[10],i;
    printf("Enter 10 numbers:");
    for(i=0;i<10;i++)
        scanf("%d",&ar[i]);
    for(i=0;i<10;i++)
        printf("%d",ar[i]);
}

When I execute this and give the following input:

1 2 3 4 5 6 7 8 9 10 11 12

I have given 12 inputs but the loop was supposed to run for only 10 times (scanf loop). I can give even more inputs and it is happy to take it unless I hit enter key. Is there something about for loop that I'm missing here?

Copyright Notice：Content Author:「imox」，Reproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/25985824/working-of-scanf-under-for-loop