Quick Reference Technical :
- Initialize single dimensional and Multi-dimensional array and printing it
Limitations of Array :
- Arrays are fixed in size.
- Arrays can hold only homogeneous data elements. (We can use object to fix it but unlike collection you cannot say that a particular type of data will be stored in it)
- Arrays are not implemented based on standard data structure hence ready-made method support is not present.
When to choose Arrays over collections
- When the size of the data is known well in advance.
- To make a collection grow-able a lot of processor time is wasted.
| Arrays | Collections |
| 1. Fixed in size | 1. Grow-able in nature |
| 2. Memory wastage is more | 2. Memory wastage is less |
| 3. Best in performance wise | 3. Not better than Arrays |
| 4. Only homogeneous datatype can he held | 4. Can hold heterogeneous datatype |
| 5. No underlying data-structure hence no ready-made method support | 5. Implemented on basis of some data structure |
| 6. Can hold primitive and non primitive data type | 6. Can hold only non primitive data-type |
Details on Arrays
- If we want to store 1000 records in a program, we cannot write 1000 variables in the program because it is a headache writing so much and secondly the readability of the program goes down. We have to use array in this case.
- We can create an array of primitive data type and objects as well.
- We need to know the size of data in advance to use array list.
- Always best to use Arrays if the size of data is fixed and known in advance i.e compile time.