The following library functions may be used by one or more of the demonstrations.

Function Description	What it does	Examples
Function isValidInteger(String s) returns Boolean	If the string s represents an integer, the function returns true; otherwise, it returns false.	isValidInteger("-34") returns true isValidInteger("27.635") returns false isValidInteger("Hello!") returns false
Function getIntegerValue(String s) returns Integer	If the string s represents an integer, the function return the integer value; otherwise, the program is terminated with an error message.	getIntegerValue("-34") returns -34 getIntegerValue("27.635") creates an error condition getIntegerValue("Hello!") creates an error condition
Function isValidFloat(String s) returns Boolean	If the string s represents a float, the function returns true; otherwise, it returns false.	isValidFloat("-34") returns true isValidFloat("27.635") returns true isValidFloat("Hello!") returns false
Function getFloatValue(s) returns Float	If the string s represents a float, the function return the float value; otherwise, the program is terminated with an error message.	getFloatValue("-34") returns -34.0 getFloatValue("27.635") returns 27.635 getFloatValue("Hello!") creates an error condition.
Function Sqrt(Float x) returns Float	If x >= 0, the function returns the square root of x; otherwise, the program is terminated with an error message.	Sqrt(16) returns 4.0 Sqrt(2.4649) returns 1.57 Sqrt(0) returns 0.0 Sqrt(-7.2) creates an error condition.