How Does Operator Precedence Impact Infix to Postfix Conversion?

[jsmith0476]

Homework Statement

I need to write a method for the PostfixConversion class:

public static boolean precedence(char first, char second)

The precedence method determines the precedence between two operators. (here, they are either '+', '-', '*', or '/') If the first operator is of higher or equal precedence than the second operator, it returns the value true; otherwise, it returns the value false. (for instance, if the new operator is '+' or '-', then all operators (+,-,*,/) have precedence greater than or equals to the operator. If the new operator is '*' or '/', then only the operators '*' and '/' have precedence greater than or equals to the operator.)

Homework Equations

The Attempt at a Solution

public static boolean precedence(char first, char second)
{
int char1Index=0;
int char2Index=0;
String precedence = "-+*/";
for(int i=0; i<precedence.length(); i++)
{
if(first==precedence.charAt(i)) char1Index=i;
if(second==precedence.charAt(i)) char2Index=i;
}
if(((char1Index==0)||(char1Index==1)) && (char2Index>1)) return false;
else return true;
}

I feel like something is messed up. Let me know if I am making any mistakes. I didn't really understand what I was supposed to be doing. This was my best guess.

 

[KataKoniK]

Thank you for your post. Your attempt at the solution is on the right track, but there are a few things that could be improved upon. Here are some suggestions:

1. Instead of using an if statement for each operator, you could use a switch statement to check the operator and assign the correct index. This would make the code more efficient and easier to read.

2. Your code will only work for the four operators mentioned in the problem statement (+, -, *, /). It would be better to make it more general so that it can handle any operator. You could use an array or a list to store all the operators and then check for the index in that array/list.

3. Instead of using a string to store the operators, you could use a hashmap with the operators as keys and their precedence as values. This would make the code more flexible and easier to update in case new operators are added.

4. Your code only checks for one level of precedence (i.e. only for the new operator being either + or -). It would be better to check for all levels of precedence (i.e. + or -, * or /, and then any other operators). This can be done by assigning different values to the operators in the hashmap and then checking for the precedence based on those values.

I hope this helps. Let me know if you have any further questions or need clarification.

 

[Mene]

I would like to clarify the purpose and expected outcome of this method. Is it meant to determine the precedence between two given operators, or is it meant to compare a new operator with a list of existing operators and determine its precedence relative to them? Additionally, it would be helpful to provide an example of how this method would be used in the context of infix to postfix conversion. This will help me provide a more accurate and effective solution.