jQuery改变了isNumeric(最新版本)? [英] jQuery's change of isNumeric (in latest versions)?
问题描述
直到最近版本,jQuery用于检查数字是否通过:
Until recent version , jQuery used to check if numeric via :
return!isNaN(parseFloat(obj))&& isFinite(obj);
第一个部分用于:
-
parseFloat(d)// Nan
-
!isNaN(parseFloat(Infinity))// true但不是数字
parseFloat("d") //Nan
!isNaN( parseFloat(Infinity)) //true but not a number
第二个部分用于:
-
isFinite('2')// true
isFinite('2') //true
但是在最近的版本中,他们更改了它并将其更改为:
But in recent version they changed it and changed it to :
return !jQuery.isArray(obj) && (obj - parseFloat(obj) + 1) >= 0;
问题:
在之前的版本中不够好,他们将其更改为新版本?为什么他们检查数组?
What was not good enough in the previous version that they changed it to the new one ? And why do they check if array?
推荐答案
obj的相同值
回答你的问题: [3]
!isNaN(parseFloat(obj) )&& isFinite(obj)
true
for [3]
。
(obj - parseFloat(obj)+ 1)> = 0
true
for [3]
。
这些问题背后的原因是转换为字符串或数字发生在< a href =http://es5.github.io/#x15.1.2.3 =noreferrer> parseFloat
和 isFinite
并且转换为字符串数组是用逗号连接其元素到字符串的转换结果。
The reason behind those problems is that a conversion to string or number occurs in parseFloat
and in isFinite
and that the conversion to string of an array is the result of joining with commas the conversion of its elements to strings.
所以这个改变是一个bug修复。
So this change is a bug fix.
请注意,您仍然可以使用 {toString:function(){return 3}}
等值使其失败,但不清楚jQuery应该返回什么在这种情况下(这个对象真的希望显示为数字,毕竟)。
Note that you can still make it "fail" with values like {toString:function(){ return 3}}
but it's unclear what jQuery should really return in such a case (this object really wants to appear as a number, after all).
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