java.util.regex.PatternSyntaxException: Dangling meta character '+' near index 0 +

Question

I am getting the error when I launch my UI that causes this code to spit the error at me in the title. It works for all of my other operator symbols so I am really not sure

Answer 1

in your case + * and ^ are treated with a special meaning, most often called as Metacharacters. String.split() method takes a regex expression as its argument and return a String array. To avoid treating above as a Metacharacters you need to use these escape sequences in your code "\\+" "\\*" "\\^"

modify your operator array like this

private String[] operators = new String[] {"-","\\+","/","\\*","x","\\^","X"};

for more detalis refere these links regex.Pattern and String.split()