Comparison Operators in LISP

In this article, we will discuss the comparison operators in LISP. These operators are used to compare numbers by taking two or more operands.

Note: This will work only on numbers,

Different comparison operators are:

Operator	Syntax	Name	Description
=	= operand1 operand2	equal to	This operator checks if the values of the operands are all equal or not, if yes, will return T(True) otherwise NIL
/=	/= operand1 operand2	not equal to	This operator checks if the values of the operands are not equal, if yes, will return NIL otherwise T (True)
>	> operand1 operand2	greater than	This operator checks if the values of the operand 1 are greater than operand 2, if yes then it returns True, otherwise NIL
<	<operand1 operand2	less than	This operator checks if the values of the operand 1 are less than operand 2, if yes then it returns True, otherwise NIL
>=	>= operand1 operand2	greater than or equal to	This operator checks if the values of the operand 1 are greater than or equal to  operand 2, if yes then it returns True, otherwise NIL
<=	<= operand1 operand2	less than or equal to	This operator checks if the values of the operand 1 are less than or equal to  operand 2, if yes then it returns True, otherwise NIL
max	max operand1 operand2	maximum number	This operator returns the maximum value.
min	min operand1 operand2	minimum number	This operator returns the minimum value.

Example: LISP Program demo on comparison operators.

Lisp

;set value 1 to 100
; set value 2 to 200
(setq val1 100)
(setq val2 200)

;check val1 is equal to val2 or not
(print (= val1 val2))

;check val1 is not equal to val2 or not
(print (/= val1 val2))

;check val1 is greater than val2 or not
(print (> val1 val2))

;check val1 is less than val2 or not
(print (< val1 val2))

;check val1 is greater than or equal to val2 or not
(print (>= val1 val2))

;check val1 is less than or equal to val2 or not
(print (<= val1 val2))

;get maximum number among val1 and val2
(print (max val1 val2))

;get minimum number among val1 and val2
(print (min val1 val2))

Output:

NIL  
T  
NIL  
T  
NIL  
T  
200  
100 

Example 2:

Lisp

;set value 1 to 20
; set value 2 to 70
(setq val1 20)
(setq val2 70)

;check val1 is equal to val2 or not
(print (= val1 val2))

;check val1 is not equal to val2 or not
(print (/= val1 val2))

;check val1 is greater than val2 or not
(print (> val1 val2))

;check val1 is less than val2 or not
(print (< val1 val2))

;check val1 is greater than or equal to val2 or not
(print (>= val1 val2))

;check val1 is less than or equal to val2 or not
(print (<= val1 val2))

;get maximum number among val1 and val2
(print (max val1 val2))

;get minimum number among val1 and val2
(print (min val1 val2))

Output:

NIL  
T  
NIL  
T  
NIL  
T  
70  
20 

Example 3: LISP program operands with equal numbers.

Lisp

;set value 1 to 50
; set value 2 to 50
(setq val1 50)
(setq val2 50)

;check val1 is equal to val2 or not
(print (= val1 val2))

;check val1 is not equal to val2 or not
(print (/= val1 val2))

;check val1 is greater than val2 or not
(print (> val1 val2))

;check val1 is less than val2 or not
(print (< val1 val2))

;check val1 is greater than or equal to val2 or not
(print (>= val1 val2))

;check val1 is less than or equal to val2 or not
(print (<= val1 val2))

;get maximum number among val1 and val2
(print (max val1 val2))

;get minimum number among val1 and val2
(print (min val1 val2))

Output:

T  
NIL  
NIL  
NIL  
T  
T  
50  
50