[자바스크립트로 구현한 알고리즘] Exes and Ohs

Description: 

Check to see if a string has the same amount of 'x's and 'o's. The method must return a boolean and be case insensitive. The string can contains any char.

Examples 

input/output: 

XO("ooxx") => true 

XO("xooxx") => false 

XO("ooxXm") => true 

XO("zpzpzpp") => true // when no 'x' and 'o' is present should return true

 XO("zzoo") => false