regular expression

reg.js

function regEx(p, w, i, j) {
  
  if( i == p.length && j == w.length )
    return true;
  
  if ( j == w.length || i == p.length )
    return false;
  
  //if second char is *
  if ( i+1<p.length && p.charAt(i+1) == '*' ){
    
    //match pre char 0 time
    if(regEx(p, w, i+2, j))
        return true;
    
  
    //match pre char 1+ times
    for(let k = j; k<w.length && (p.charAt(i)==w.charAt(k) || p.charAt(i) == '.'); k++) {
       if(regEx(p, w, i+2, k+1))
          return true;
    }
    
  }
  
  
  if(p.charAt(i) == w.charAt(j) || p.charAt(i) == '.') {
     if(regEx(p, w, i+1, j+1))
        return true;
  }
        
  return false;
  
}