javascript“关联”数组访问
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/2524413/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
javascript "associative" array access
提问by cp.
I have a simple simulated aarray with two elements:
我有一个带有两个元素的简单模拟数组：
bowl["fruit"]="apple";
bowl["nuts"]="brazilian";
I can access the value with an event like this:
我可以通过这样的事件访问该值：
onclick="testButton00_('fruit')">with `testButton00_`
function testButton00_(key){
var t = bowl[key];
alert("testButton00_: value = "+t);
}
However whenever I try to access the aarray from within code with a key that is just a non-explicit string I get undefined. Do I have somehow have to pass the parameter with the escaped 'key'. Any ideas? tia.
但是，每当我尝试使用一个非显式字符串的键从代码中访问数组时，我都会得到未定义。我是否必须以某种方式使用转义的“键”传递参数。有任何想法吗？蒂亚。
回答by Daniel Earwicker
The key can be a dynamically computed string. Give an example of something you pass that doesn't work.
键可以是动态计算的字符串。举一个你通过但不起作用的例子。
Given:
鉴于：
var bowl = {}; // empty object
You can say:
你可以说：
bowl["fruit"] = "apple";
Or:
或者：
bowl.fruit = "apple"; // NB. `fruit` is not a string variable here
Or even:
甚至：
var fruit = "fruit";
bowl[fruit] = "apple"; // now it is a string variable! Note the [ ]
Or if you really want to:
或者，如果您真的想：
bowl["f" + "r" + "u" + "i" + "t"] = "apple";
Those all have the same effect on the bowlobject. And then you can use the corresponding patterns to retrieve values:
这些都对bowl对象具有相同的效果。然后您可以使用相应的模式来检索值：
var value = bowl["fruit"];
var value = bowl.fruit; // fruit is a hard-coded property name
var value = bowl[fruit]; // fruit must be a variable containing the string "fruit"
var value = bowl["f" + "r" + "u" + "i" + "t"];
回答by douwe
I am not sure I understand you, you can make sure the key is a string like this
我不确定我是否理解您，您可以确保密钥是这样的字符串
if(!key) {
return;
}
var k = String(key);
var t = bowl[k];
Or you can check if the key exists:
或者您可以检查密钥是否存在：
if( typeof(bowl[key]) !== 'undefined' ) {
var t = bowk[key];
}
However I don't think you have posted the non working code?
但是我认为您没有发布非工作代码？
回答by Raj Kaimal
You could use JSON if you dont want to escape the key.
如果您不想转义密钥，可以使用 JSON。
var bowl = {
fruit : "apple",
nuts : "brazil"
};
alert(bowl.fruit);
