Module 9: Array processing and Table handling

COBOL- Difference between Subscript and Index

Subscript	Index
Denotes position/occurrence of the element in an array	Denotes displacement of the element from beginning of an array
Declared in WORKING-STORAGE SECTION separately	No need to declare in WORKING-STORAGE SECTION
Occurrence is converted into displacement to access array element thus, slower.	Since it already denotes displacement, thus no conversion needed. This makes it faster and efficient
It is valid to use subscript in arithmetic operation or for display	It is invalid to use INDEX in arithmetic operation or for display
Subscript modification is possible with any arithmetic operation	INDEX modification is possible only with SET, SEARCH and PERFORM