Answers for "c ways of getting array length"

size of an array c

int a[20];
int length;
length = sizeof(a) / sizeof(int);

size of an array c

int a[]= { 1, 2, 3, 4, 5, 6, 7 };
int length = sizeof(a) / sizeof(a[0]); //return 7

find length of array in c

int a[17]; // initializing an array
int length = sizeof(a)/sizeof(a[0]); // divide array size(in byte)/ size of the first element of the array of the same type, here int(integer size is 4byte)