The AutoLisp Intermediate Tutorial

Number Functions

   abs     atof     atoi      fix     float      itoa     Example Program

  abs - This function returns the absolute value of a number.

            Syntax : (abs number)

            number - any valid number.[integer or real number]

             Returns an integer or a real number.

                 (abs 345) returns 345

                 (abs 345.5) returns 345.5

                 (abs -345) returns 345

                 (abs -345.5) returns 345.5

                 (abs "345JEFF") returns "Error: Bad Argument Type"   ["345JEFF" is a string, not a number]

  atoi - This function converts a string to a integer.

            Syntax : (atoi "string")

            "string" - any valid string or variable representing a string.  If you use a variable omit the quotes.

             Returns an integer.

                 (atoi "Jeff345") returns 0

                 (atoi "5") returns 5

                 (atoi "5.6") returns 5

                 (atoi "") returns 0

                 (atoi "345JEFF") returns 3

                 (atoi 5) returns "Error: Bad argument type".       [5 is an integer, not a string]

                 (atoi 5.6) returns "Error: Bad argument type".   [5.6 is a real number, not a string]

             This function looks at the first character, then the next, then the next,  ect.  until it finds a character that                cannot be part of an integer.

  itoa - This function converts an integer to a string.

            Syntax : (itoa integer)

            integer - Any valid integer.

             Returns a string.

                 (itoa 345) returns "345"

                 (itoa 5) returns "5"

                 (itoa 5.6) returns "Error: Bad argument type".  [5.6 is a real number, not an integer]

                 (itoa "5") returns "Error: Bad argument type".  ["5" is a string not an integer]

                 (itoa "345JEFF") returns "Error: Bad argument type".  ["345JEFF" is a string, not an integer]

              This function can only accept an integer or a variable representing an integer as it's parameter. 

  atof - This function converts a string to real. 

            Syntax : (atof "string")

            "string" - any valid string or variable representing a string.  If you use a variable omit the quotes.

             Returns an real number.

                 (atof "Jeff345") returns 0.0

                 (atof "5") returns 5.0

                 (atof "5.6") returns 5.6

                 (atof "5'3-1/2"") returns 63.5

                 (atof "3-1/2"") returns 3.5

                 (atof "") returns 0.0

                 (atof "345JEFF") returns 345.0

                 (atof 345) returns "Error: Bad Argument Type"    [345 is an integer, not a string]

                 (atof 3.4) returns "Error: Bad Argument Type"    [345 is a real number, not a string]

                 (atof (list 3 4)) returns "Error: Bad Argument Type"    [(list 3 4) is a list, not a string]

              This function looks at the first character, then the next, then the next,  ect.   until it finds a character that                cannot be part of an real number.

  fix - This function converts a real to an integer.

            Syntax : (fix real)

              real - Any valid real number.

             Returns an integer.

                 (fix 345.0) returns 345

                 (fix 5.0) returns 5

                 (fix 5.6) returns 5

                 (fix "5.0") returns "Error: Bad Argument Type     ["5.0" is a string, not a real number]

                 (fix "5") returns "Error: Bad Argument Type          ["5" is a string, not a real number]

              This function takes the whole number part of a decimal number and returns it as an integer.

  float - This function takes a number (integer or real) and converts it to a real number.

             Syntax : (float integer) (float real)

             Integer - Any valid integer.

             real - Any valid real number.

                (float 5) returns 5.0

                (float 345) returns 345.0

                (float 3.5) returns 3.5   [No effect, but no error]

                (float "3") returns "Error: Bad Argument Type"       ["3" is a string, not a number]

                (float "3.5") returns "Error: Bad Argument Type"   ["3.5" is a string, not a number]

                (float "abc") returns "Error: Bad Argument Type"  ["abc" is a string, not a number]

Example Program 1:

(defun C:myProg()

  (setq intAge(getint "\n Enter your Age: "))

  (setq intDays(* intAge 365))                

  (princ (strcat "\n You are " (itoa intDays) " Days old!"))

  (princ)

) 

Execution:

Command: (load "myProg")<enter>

Command: myProg<enter>

Command:  Enter your Age: 39<enter>

Command: You are 14235 Days old!

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