JavaScript_Funny ParseInt

 var num1 = "01"; //1

 var num7 = "07"; //7

 var num8 = "08"; //0

 var num9 = "09"; //0

 var num10 = "010"; //8

 alert( parseInt(d) ); 

 为什么会这样子？

 看看parseInt这个函数:

parseInt(string, radix) 

Parameter	Description
string	Required. The string to be parsed
radix	Optional. A number (from 2 to 36) that represents the numeral system to be used

 If the radix parameter is omitted, JavaScript assumes the following:

• If the string begins with "0x", the radix is 16 (hexadecimal)
• If the string begins with "0", the radix is 8 (octal). This feature is deprecated
• If the string begins with any other value, the radix is 10 (decimal)

Tips and Notes

Note: Only the first number in the string is returned!

Note: Leading and trailing spaces are allowed.

Note: If the first character cannot be converted to a number, parseInt() returns NaN.

 

Browser 认为字符串第一个字符带0就是八进制数值，八进制也只有0~7。 parseInt(d, 10)就Ok了。