int highNum = 0;
int m;
int list[4] = {10, 4, 7, 8};
for (m = 0 ; m < size ; m++);
{
if (list[m] > highNum)
highNum = list[m];
You put a superfluous at the end ; in :
for (m = 0 ; m < size ; m++);
Edit : Working code with some additional << endl;
int size = 4;
int highNum = 0;
int m;
int list[4] = {10, 4, 7, 8};
for (m = 0 ; m < size ; m++)
{
if (list[m] > highNum)
highNum = list[m];
cout << list[m] << endl;
}
cout << highNum << endl;