[英]Cannot access object property using variable
I have an object that looks like this: 我有一个看起来像这样的对象:
var set_1 = {
id: 'set_1',
nameofSet : 'English fruits',
category: 'languages',
cards : [
{
front : 'apple',
back : 'jablko'
},
{
front : 'orange',
back : 'pomarancza'
},
{
front : 'pear',
back : 'gruszka'
}
]
}
Now there's a function: 现在有一个功能:
$('#chooseSet').on('click', '.setName', function() {
var setName = this.getAttribute("data-set-name");
editCards(setName);
});
This is the HTML: 这是HTML:
<div class="setName" data-set-name="set_1">English fruits</div>
It gives the setName
parameter to the editCards
function that looks like this: 它将
setName
参数提供给editCards
函数,如下所示:
editCards(setName) {
console.log(setName); // logs "set_1"
console.log(setName.cards); // logs "undefined" - why?
console.log(set_1.cards); // logs the `cards` array from `set_1'.
// code
}
It takes the setName
parameter. 它使用
setName
参数。
My question is - why doesn't the second console.log
give me the cards' array as it does in the third
console.log` example? 我的问题是-为什么第二个
console.log
cards' array as it does in the third
console.log例子cards' array as it does in the third
给我cards' array as it does in the third
?
Because any attribute's value is a string. 因为任何属性的值都是字符串。 So in your case
data-set-name
returns the string "set_1"
, which is not a reference to the variable set_1
. 因此,在您的情况下,
data-set-name
返回字符串"set_1"
,而不是对变量set_1
的引用。 If your set_1
variable is global, you should be able to do this instead - 如果您的
set_1
变量是全局变量,则应该可以执行以下操作-
console.log(window[setName].cards)
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.