数组长度返回 0 [英] Array Length returns 0

问题描述

谁能帮忙解释为什么长度返回0?非常感谢您！

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

因为这不是您添加项目的方式，因为数组只接受数字键.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，如果您将它用作对象，'' 也不是有效名称.

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

*更正:看起来您可以使用 ""(空字符串)作为键.

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

这篇关于数组长度返回 0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IT屋！