LISP : Practice Questions and Answers

In LISP programming, Symbols can be considered all of these. Mostly these are known as data objects and sometimes are also known as data structures or data types.

It works same as (write 'argument) because LISP is case insensitive language.

LISP is not a case sensitive language. Example: (print 'a) will behave same as (PRINT 'A).

An empty thing is also considered as List. Empty thing means the braces () with no arguments. Numbers are not counted in Lists.

Atoms consist of Literals, Numbers, Integers, Ratios, Flonum. Lists are formed from atoms. Cons of two atoms is referred to as List.

According to recursive definition of S-expression if S1, S2, S3... are S-expressions then list: (S1 S2 S3 ....) is also an S-expression. S-expression is short form of symbolic expressions.

Both integerp and zerop will be same when both will show either T or NIL. Both will show T when argument is 0 and NIL when argument is not an integer.

It is the predicate used to check whether the argument is zero or not. It will show T (true) only if the argument is numeric zero, that is, 0 and NIL in all other cases.

Atom, symbolp, listp, numberp all are considered as data type predicates. Atom is used check if an argument is atom or not. Similarly, symbolp is used to check symbols, listp to check lists and numberp to check whether the argument is a number or not.

Eql is used by member argument to compare between its two arguments. Eql is one of the equality predicates and is used to test for numbers and symbols of the same type.

The full form of setf is set field and it means that it sets the field with the value given.

In the process of assigning values to multiple variables with setf and setq, the setf and setq prints only the last value assigned to a variable. It does not print all the values.

The setf and setq takes any number of arguments but the number must be even. Even is required because one of the two will be value taker and another one will be value giver. So, it always comes in a pair.

Setq is used only for symbols and setf is used for any data type, so Setf can be used in place of setq but setq cannot be used in place of setf.

Setq is used only for setting the values of symbols but setf can be used for anything. Setf can be used for setting value of any data-type and not only symbols.

Syntax of the LISP takes prefix expressions. So, 6/3=2 and 6-4=2 will be the outputs of the following statements.

Output: 2,2

Yes, the arithmetic operators are primitives in LISP programming language. For example: in (/ 3 3) / is a primitive.

Cons is the primitive used to add an element to list. Cons take two lists as an argument and merge them to form a new list.

Delete is the primitive used to remove an element from list. The element to be removed is passed as an argument to delete primitive along with the list name from which element is to be deleted and delete will remove that element from list.

Setf is used to create the list. Getf is used to retrieve the data from list. Make is not a primitive in LISP.