Arrays are useful when planning the detailed layout of memory and sometimes can help avoid allocation.

[<length>]<element_type>{,..,}
[N]Type
[N]Type{value1, value2, ..., valueN}
[...]Type{value1, value2, ..., valueN}

Planning to store a student who has a maximum of 5 subjects scores and is not a dynamic subject.

myStudentscores := [5]int{50,90,80,60,70}
The compiler will have a fixed memory allocation 5 individual integer size for myStudentscores with initializing values. This avoids of allocation of memory that gets unused.
Note: [5]int it length is part of a type. So [4]int is not the same type [5]int. As result equal operation comparison of both result in compile time error of type mismatch.