Problem in a line of code.

Question

//Program to calculate even or odd
#include<stdio.h>
#include<string.h>
int main()
{
char array[1000001];
long long int i,test,len;
scanf("%lld",&test);
for(i=0;i<test;i++)
{
scanf("%s",array);
len=strlen(array);
if(array[len-1]%2==0)
printf("YES\n");
else
printf("NO\n");
}
}

The code above works perfectly fine.
My question is that why in "if(array[len-1]%2==0)" array[len-1] is taken rather than taking array[len]?

Answer 1

Array[len] is out of bounds. Arrays start counting as 0, instead of 1, meaning they have one less indices than the length.