What language are you after?
You can use the sizeof() function in C/C++:
printf("Size of array: %lu\n", sizeof(array));
printf("Element count in array: %lu\n", sizeof(array) / sizeof(array));
In other object-oriented languages, such as Java, C#, you typically have a Length or Count property on collections.
using this Method in Swift
var a = [4,53,45,32,67]