1. What is COBOL?
COBOL is abbreviated as Common Business Oriented Language and it is one of the oldest programming languages. It primarily used for business, finance and administrative systems for companies.

2. What are the different data types in COBOL?
There are three data types in Cobol:Alpha-numeric (X),Alphabetic (A) and Numeric (9)

3. What is the difference between subscript and index?
Subscript refers to the occurrence of an array but index is the displacement from the beginning of the array.An index can only be modified using PERFORM, SEARCH & SET.

4. What is the difference between performing a SECTION and a PARAGRAPH?
SECTION will have all the paragraphs that are part of the section, to be performed.PARAGRAPH will have only that paragraph to be performed.

5. What is the difference between CONTINUE & NEXT SENTENCE?
CONTINUE is like a null statement and it continues execution, while NEXT SENTENCE transfers control to the next sentence.

6. What are the different OPEN modes available in Cobol?
Input, Output, Input – Output and Extend

7. What is Static and Dynamic linking?
In static linking, called subroutine links into the calling program, while in dynamic linking, the subroutine & the main program will exist as separate modules. Dynamic and Static linking can be achieved by choosing either the DYNAM or NODYNAM link edit option.

8. What is the use of EVALUATE statement?
Evaluate is just like a case statement or it can be used like a Nested IFs. The difference between EVALUATE and case is that ‘break’ is not used in Evaluate statement and the control comes out of the EVALUATE once a match is found.

9. What is the difference between PERFORM ... WITH TEST AFTER and PERFORM ... WITH TEST BEFORE?
If TEST BEFORE is specified, the condition is tested at the beginning of each repeated execution of the specified PERFORM range; If TEST AFTER is specified, the condition is tested at the end of the each repeated execution of the PERFORM range. The range is executed at least once in TEST AFTER.

10. What is the point of the REPLACING option of a copy statement?
REPLACING allows for the same copy to be used more than once in the same code by changing the replace value.