Javascript警报号码从0开始 [英] Javascript alert number starting with 0

问题描述

我有一个按钮，在后面的代码中我添加了 onclick ，我传递了一个唯一的ID，它将被传递给js函数。 id以0开头。

I have a button where in the code behind I add a onclick and I pass a unique ID which will be passed to the js function. The id starts with a 0.

它无法正常工作，最终我发现数字，ID，传递错误...

It wasn't working and eventually I figured out that the number, id, it was passing was wrong...

即。看到这个： js fiddle

它适用于'在数字的开头和结尾。只是想知道为什么013转到11.我做了一些谷歌搜索，找不到任何东西......

It works with a ' at the start and end of the number. Just wondering why 013 turns to 11. I did some googling and couldn't find anything...

干杯

Robin

编辑：

谢谢大家。是的，现在明白了。

Thanks guys. Yep understand now.

在这种情况下，开头的0有意义，这里是邮件列表中的收件人ID，我将使用'013'而不是013，即a串。然后，我可以将值分成js，因为3个值中的每一个代表一个不同的id，它总是只有1个字符长，即0-9。

As in this case the 0 at the start has a meaning, here the recipient ID in a mailing list, I will use '013' instead of just 013, i.e. a string. I can then split the values in js as each of the 3 values represents a different id which will always be only 1 character long, i.e. 0-9.

推荐答案

以 0 开头的数字文字被视为八进制数。所以基数8中的13是基数10中的11 ...

A numeric literal that starts with a 0 is treated as an octal number. So 13 from base 8 is 11 in base 10...

八位数字文字已被弃用，但如果你没有处于严格模式，它仍然可以工作。

Octal numeric literals have been deprecated, but still work if you are not in strict mode.

（你没有问，但是）以 0x 开头的数字文字被视为十六进制。

(You didn't ask, but) A numeric literal that starts with 0x is treated as hexadecimal.

更多信息，请访问 MDN 。

在您的演示中，参数名为 id ，这意味着你不要需要对它进行数值运算 - 如果是这样，只需将其放在引号中并将其用作字符串。

In your demo the parameter is called id, which implies you don't need to do numerical operations on it - if so, just put it in quotes and use it as a string.

如果你需要能够传递一个前导零但仍然将数字视为基数10来对其进行数值运算，您可以将其括在引号中以将其作为字符串传递，然后将字符串转换为强制基数为10的数字，例如：

If you need to be able to pass a leading zero but still have the number treated as base 10 to do numerical operations on it you can enclose it in quotes to pass it as a string and then convert the string to a number in a way that forces base 10, e.g.:

something('013');

function something(id){    
    alert(+id);             // use unary plus operator to convert
    // OR
    alert(parseInt(id,10)); // use parseInt() to convert        
}

演示： http://jsfiddle.net/XYa6U/5/

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