javascript parseInt&Number函数的区别

在js中,如果你使用parseInt("08"),一般都会认为会返回8,然而实际上返回了0.但是用Number("08")返回的才是8.

但是parseInt("08", 10)是可以返回8的。

为搞清楚两者的区别,

参考了别人写的parseInt&Number的区别:

parseInt  
  Parses   a   string   argument   and   returns   an   integer   of   the   specified   radix   or   base.  
  核心函数      
  实现版本   Navigator   2.0:   If   the   first   character   of   the   string   specified   in   parseInt(string)   cannot   be   converted   to   a   number,   returns   "NaN"   on   Solaris   and   Irix   and   0   on   all   other   platforms.Navigator   3.0,   LiveWire   2.0:   Returns   "NaN"   on   all   platforms   if   the   first   character   of   the   string   specified   in   parseInt(string)   cannot   be   converted   to   a   number.      
   
   
   
  语法  
  parseInt(string,radix)    
  参数  
  string   A   string   that   represents   the   value   you   want   to   parse.    
  radix   (Optional)   An   integer   that   represents   the   radix   of   the   return   value.    
   
   
   
  描述  
  The   parseInt   function   is   a   built-in   JavaScript   function.  
  The   parseInt   function   parses   its   first   argument,   a   string,   and   attempts   to   return   an   integer   of   the   specified   radix   (base).   For   example,   a   radix   of   10   indicates   to   convert   to   a   decimal   number,   8   octal,   16   hexadecimal,   and   so   on.   For   radixes   above   10,   the   letters   of   the   alphabet   indicate   numerals   greater   than   9.   For   example,   for   hexadecimal   numbers   (base   16),   A   through   F   are   used.  
   
  If   parseInt   encounters   a   character   that   is   not   a   numeral   in   the   specified   radix,   it   ignores   it   and   all   succeeding   characters   and   returns   the   integer   value   parsed   up   to   that   point.   parseInt   truncates   numbers   to   integer   values.  
   
  If   the   radix   is   not   specified   or   is   specified   as   0,   JavaScript   assumes   the   following:  
   
   
   
  If   the   input   string   begins   with   "0x",   the   radix   is   16   (hexadecimal).    
   
  If   the   input   string   begins   with   "0",   the   radix   is   eight   (octal).    
   
  If   the   input   string   begins   with   any   other   value,   the   radix   is   10   (decimal).    
  If   the   first   character   cannot   be   converted   to   a   number,   parseInt   returns   "NaN".  
  For   arithmetic   purposes,   the   "NaN"   value   is   not   a   number   in   any   radix.   You   can   call   the   isNaN   function   to   determine   if   the   result   of   parseInt   is   "NaN".   If   "NaN"   is   passed   on   to   arithmetic   operations,   the   operation   results   will   also   be   "NaN".  
   
   
  示例  
  The   following示例   all   return   15:  
  parseInt("F",   16)  
  parseInt("17",   8)  
  parseInt("15",   10)  
  parseInt(15.99,   10)  
  parseInt("FXX123",   16)  
  parseInt("1111",   2)  
  parseInt("15*3",   10)   The   following示例   all   return   "NaN":  
   
  parseInt("Hello",   8)  
  parseInt("0x7",   10)  
  parseInt("FFF",   10)   Even   though   the   radix   is   specified   differently,   the   following示例   all   return   17   because   the   input   string   begins   with   "0x".  
   
  parseInt("0x11",   16)  
  parseInt("0x11",   0)  
  parseInt("0x11")    
  -----------------------------------------------  
  -----------------------------------------------  
  将指定对象转换为数字。    
  核心函数        
  实现版本     Navigator   4.0,   Netscape   Server   3.0    
   
  语法  
  Number(obj)    
  参数  
  obj     一个对象。    
   
   
   
  描述  
  如果对象是   Date   类型的对象,Number   将返回自格林威治标准时间   1970   年   1   月   1   日起已经经过的毫秒数,在此日期之后的是正数,之前的是负数。    
  如果   obj   是一个没有数字格式的字符串,Number   将返回   NaN。    
   
   
  示例  
  下面的例子将把   Date   对象转换为数值型值:    
  <SCRIPT>  
  d   =   new   Date   ("December   17,   1995   03:24:00");    
  document.write   (Number(d)   +   "<BR>");  
原文地址:https://www.cnblogs.com/si812cn/p/1652168.html