java
public boolean isNumeric(String str){ Pattern pattern = Pattern.compile("^-?[0-9]+\\.?[0-9]+"); Matcher isNum = pattern.matcher(str); if( !isNum.matches() ){ return false; } return true; }
python
def isNum(value): try: int(value) + 1 except: return False else: return True
oracle
create or replace function func_is_number( sx in varchar) return int is x number; begin x:=to_number(sx); return 1; exception when others then return 0; end;