javascript 형변환

eval()                          수식 또는 문자열(계산)  →   실수                              
Number()                    문자                            →   숫자                              
String()                       숫자                            →   문자                              
escape()                      한글                           →  16진수                            
unescape()                  16진수                        →   한글                              
parseInt(문자열, 진수)   문자열                         →   정수(원하는 진수 변환 가능)       
parseFloat()                 문자열                        →   부동소수점, 변환불가일때 NaN 반환 
isFinite()                     유한수 TRUE,   무한수  FALSE                             
isNan()                       문자    TRUE,   숫자     FALSE