数组长度返回0 [英] Array Length returns 0

问题描述

任何人都可以帮忙解释为什么长度返回0？非常感谢您提前！

Could anyone help explain why length is returning 0? Thank you VERY much in advance!

var errors = [];
errors[''] = "Monday Morning slot already taken. Would you like to replace it?";
console.log(errors);
document.write(errors.length);

推荐答案

因为这不是你添加项目的方式，因为Arrays只接受数字键。你这样做：

Because that is not how you add an item since Arrays only accept numeric keys. You do it like this:

errors.push("blah");  /*or*/  errors[0] = "blah";

//Now if you check the length:
errors.length;  //1

此外，如果您将其用作对象，' ' 也不是有效名称。

Also, if you are using it as an Object, '' isn't a valid name either.

*更正：看起来你可以使用（空字符串）作为键。

*Correction: Looks like you can use "" (empty string) as a key.

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