本文介绍了有效的假值的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
任何值转换为布尔收益假或真正。例如：
Converting any value to Boolean returns false or true. For example:
> Boolean (false)
false
> Boolean (null)
false
> Boolean (undefined)
false
> Boolean ("")
false
但 0 是特殊的，因为它是一个数字。我考虑的是作为一个有效的假值：
But 0 is special, because it's a number. I consider is as a valid false value:
> Boolean (0)
false
是否有任何其他的有效的假值？
推荐答案
根据 ECMA标准5.1 ，一个前pression的感实性将是决定，如下表每
As per ECMA 5.1 Standards, Truthiness of an expression will be decided, as per the following table
+---------------+-------------------------------------------------------+
| Argument Type | Result |
+---------------+-------------------------------------------------------+
| Undefined | false |
+---------------+-------------------------------------------------------+
| Null | false |
+---------------+-------------------------------------------------------+
| Boolean | The result equals the input argument (no conversion). |
+---------------+-------------------------------------------------------+
| Number | The result is false if the argument is +0, −0, or NaN;|
| | otherwise the result is true. |
+---------------+-------------------------------------------------------+
| String | The result is false if the argument is the empty |
| | String (its length is zero); otherwise the result is |
| | true. |
+---------------+-------------------------------------------------------+
| Object | true |
+---------------+-------------------------------------------------------+
所以，你已经错过了 -0 和 NaN的。
console.log(Boolean(-0));
# false
console.log(Boolean(NaN));
# false
这篇关于有效的假值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！