i was so confused the elimination of parenthesis in this equation just like:
(a+(b+c)+d) into a+b+c+d

the outcome of this code: instead of deleting a parenthesis, it is an error...how to correct that problem since my approach is to convert complicated expressions to simpler form using elimination of parenthesis?

i hope, you partially answer this problem

Hi there!

You should put character literals between single quotes, otherwise the compiler won't interpret them as characters.

Example:


Inside your for-loop, the compiler thinks that your parenthesis are part of the code when, in reality, you wish to test if the variable op equals the character '(' or ')' (at least that is my interpretation).

Good luck with your application!

aside from detecting a '(' or ')' how to delete if it is equal to that character?
just like:


output

I don't think delete is a word in Java. When you try to delete the characters, you write:

but the compiler will think that it's a variable declaration were delete is the type and that c is the name of the variable. It will issue an error (unless you really do have a class called "delete" in your program ).

You could, for each character, check to see if it is a '(' or ')', and if it isn't then you print it. For instance:

This approach doesn't really delete the characters, but it ignores them. If you really need to delete them, you can try some of the following:

If you want to store the output (e.g. in a String) rather than sending it to the screen, you should check out one overloaded method of the String class: substring().

The substring() method comes in two versions, this is what the Java API specification says about these two methods:



Example (also from the specification):
"hamburger".substring(4, 8) returns "urge"

Again, we don't delete the character, but we create a new string that contains all character except for the ')' or the '('. Sometimes it's a real pain that the String objects are immutable .

If you have long expressions, the above method isn't really effective, because there will be a lot of copying, and you should look for other solutions. Another class that is great when analysing String objects is the StringTokenizer class in the java.util package. I encourage you to read about it, and that you can do here.

You seem to know a lot about Java, so I figured that general guidelines would be a better way to help rather than just posting a complete solution. I hope they were usefull to you, if you're still having problems, just post here and we'll see what can be done.