检查所有int数组元素是否都等于特定数字的最短代码？

Question

What's the shortest way I can do an if..else statement to check if all int array elements are equal to certain numbers? For example in pseudocode:

if (allElementsOfIntArray == -1)
   //do something
else if (allElementsOfIntArray == 1)
  //do something else

I have another variable that is const int arraySize

My Arduino code is getting really messy at this point so I'm just trying to find the shortest way to implement this so it doesn't look like a mess to others that have to read it.

Answer 1

bool all_are(int* i_begin, std::size_t sz, int x)
{
    const int* i_end = i_begin + sz;
    for(; i_begin != i_end; ++i_begin)
        if(*i_begin != x) return false;

    return true;
}

if (all_are(my_array, arraySize, -1))
   //do something
else if (all_are(my_array, arraySize, 1))
  //do something else

Answer 2

Check first if all entries are the same and then switch() :

for (int i=1; i<arraysize; i++)
   if (theArray[0] != theArray[i]) return "no way";

/*** All array elements are the same, so we can evaluate any element ***/

switch (theArray[0]) 
{
   case 0:
        return "All are zero";
   case 1:
        return "All are one";
   default:
        return "All elements are the same";
}

Answer 3

The quickest way that pops into mind (assuming the array is unsorted) is to just iterate through it and checking each element. You can do this a few ways. Use a normal for loop or try a for each .

Answer 4

Each element in array is independent to others. So you must use for to check all of it to make sure.