how to check the length of an array in c code example

Example 1: size of an array c

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

int prices[5] = { 1, 2, 3, 4, 5 };

int size = sizeof prices / sizeof prices[0];

printf("%u", size); /* 5 */

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

int a[17];
size_t n = sizeof(a)/sizeof(a[0]);

// In Javascript
var x = [1,2,3];
console.log(x.length);