Class myArithmetic

java.lang.Object
  myArithmetic

public class myArithmetic
extends java.lang.Object

The myArithmetic class receives an arithmetic expression in the form of a String and evaluates it. For example, if the class receives the String "5-4-3" it prints the result -2.

Constructor Summary

myArithmetic()
The constructor allocates memory for the two ArrayStack objects that the class employs.

Method Summary

java.lang.String	doCalculation(java.lang.String firstS, java.lang.String secondS, java.lang.String oper) performs the appropriate math and returns the result
java.lang.String	evaluateString(java.lang.String s) this main method of the class evaluates the arithmetic expression
boolean	isNumber(java.lang.String s) figures out if the parameter is a number
boolean	isOperator(java.lang.String s) figures out if the parameter is an operator
boolean	isSpace(java.lang.String s) figures out if the parameter is a space
static void	main(java.lang.String[] args) main creates a myArithmetic object, calls the 'evaluateString()' method and prints the result
int	precedence(java.lang.String s) Returns the precedence of a given operator: ^ * / + -

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

myArithmetic

public myArithmetic()

The constructor allocates memory for the two ArrayStack objects that the class employs.

Method Detail

precedence

public int precedence(java.lang.String s)

Returns the precedence of a given operator: ^ * / + -

Parameters:

s - String whose precedence is to be determined

Returns:

the String's precedence (an int)

isOperator

public boolean isOperator(java.lang.String s)

figures out if the parameter is an operator

Parameters:

s - the String which may be an operator

Returns:

true if the parameter is an operator

isNumber

public boolean isNumber(java.lang.String s)

figures out if the parameter is a number

Parameters:

s - the String which may be a number

Returns:

true if the parameter is a number

isSpace

public boolean isSpace(java.lang.String s)

figures out if the parameter is a space

Parameters:

s - the String which may be a space

Returns:

true if the parameter is a space

doCalculation

public java.lang.String doCalculation(java.lang.String firstS,
                                      java.lang.String secondS,
                                      java.lang.String oper)

performs the appropriate math and returns the result

Parameters:

first - the first number in the calculation

second - the second number in the calculation

oper - the operator in the calculation

Returns:

a String that is the result of the calculation

evaluateString

public java.lang.String evaluateString(java.lang.String s)

this main method of the class evaluates the arithmetic expression

Parameters:

s - String to be evaluated

Returns:

the result of performing the calculation, in String form

main

public static void main(java.lang.String[] args)

main creates a myArithmetic object, calls the 'evaluateString()' method and prints the result