find specific string pattern in text using regular expression in java

Question

I need to find the regular expression to use as an argument in string.matches. I have a text of strings separated by space " " and i want to find what type of Number is it. First of all i need to check pattern like this: "[number] E [number] & [number]". & is a symbol in the string, so is E.

// so *word* is a string tested       
if (word.matches("\d++ E *\d++ & \d++")) *something like that*

For example "1001Ε101&2" is true and "0114&2" is false.

So I need the regular expression in word.matches(" *answer* ");

It's a project in lexical analysis. I must not use ready lexers.

Answer 1

Your regex is almost right. Simply use it this way:

Pattern.matches("\\d++ *E *\\d++ *& *\\d++", word);

with word the string to check.

Don't forget to use a double \ in your regex string where you would put a simple \.