javascript 未捕获的类型错误：尝试访问对象时在非对象上调用了 Object.keys
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Uncaught TypeError: Object.keys called on non-object while trying to access object
提问by apaleja
I am trying to access array inside object using Object.keys(obj.arr));method. If I access array directly like below, then it is giving proper output:
我正在尝试使用Object.keys(obj.arr));方法访问对象内部的数组。如果我像下面一样直接访问数组，那么它会提供正确的输出：
alert(Object.keys(obj.arr));
but if I pass array name using parameter then it is giving error :
但是如果我使用参数传递数组名称，则会出现错误：
var selected = "arr";
alert(Object.keys(obj.arr));
error : Uncaught TypeError: Object.keys called on non-object
There is example : DEMO
有例子：DEMO
采纳答案by Esailija
If you need dynamic property access, you cannot use .value. That is always literally accessing named key of "value". If you want to access property with the key name contained in the variable valueyou need to use brackets: obj[value]
如果您需要动态属性访问，则不能使用.value. 那总是从字面上访问 的命名键 "value"。如果要value使用变量中包含的键名访问属性，则需要使用方括号：obj[value]
Fixed demo: http://jsfiddle.net/Lv6TY/7/
固定演示：http: //jsfiddle.net/Lv6TY/7/
console.log("Variable Pass "+Object.keys(groups[selected]));
