使用 underscore.js findWhere 函数时如何为属性名称使用变量? [英] How to use a variable for a property name when using underscore.js findWhere function?

问题描述

我在使用 _.findWhere 函数时无法弄清楚如何在 underscore.js 中动态设置属性.

这是该函数的文档:

<块引用>

findWhere_.findWhere(list, properties)

查看列表并返回匹配所有列表的第一个值属性中列出的键值对.

如果没有找到匹配项，或者列表为空，则返回 undefined.

_.findWhere(publicServicePulitzers, {newsroom: "The New York Times"});=>{年份:1918，新闻编辑部:纽约时报"，理由:因为它为公众服务，完整地发布了这么多官方报告，欧洲政治家关于进步和发展的文件和演讲战争的进行."}

建模文档中的例子，我想设置属性来动态搜索:

 var publicServicePulitzers = [{"newsroom":"The New York Times", "year":2013 },{"newsroom":"The Los Angeles Times", "year":2012 }];var myprop = '新闻室';_.findWhere(publicServicePulitzers, { myprop : "纽约时报"});

结果未定义.

我也试过:

_.findWhere(publicServicePulitzers, {eval(myprop): "The New York Times"});

错误信息是 SyntaxError: missing : after property id

我怎样才能做到这一点?

感谢您的帮助.

解决方案

刚刚想通了.findWhere 的第二个参数是一个对象.所以首先创建对象并将其传递给函数:

var myprop = 'newsroom';var value = '纽约时报';var search_obj = {};search_obj[myprop] = 值；var 结果 = _.findWhere(publicServicePulitzers,search_obj);

有效！

I'm having trouble figuring out how to set a property dynamically in underscore.js while using the _.findWhere function.

Here's the documentation for the function:

findWhere_.findWhere(list, properties) 

Looks through the list and returns the first value that matches all of the key-value pairs listed in properties.

If no match is found, or if list is empty, undefined will be returned.

_.findWhere(publicServicePulitzers, {newsroom: "The New York Times"});
=> {year: 1918, newsroom: "The New York Times",
reason: "For its public service in publishing in full so many official reports,
documents and speeches by European statesmen relating to the progress and
conduct of the war."}

Modeling the example in the docs, I want to set the property to search for dynamically:

 var publicServicePulitzers = [
    {"newsroom":"The New York Times", "year":2013 },
    {"newsroom":"The Los Angeles Times", "year":2012 }
 ];

var myprop = 'newsroom';
_.findWhere(publicServicePulitzers, { myprop : "The New York Times"});

The result is undefined.

I also tried:

_.findWhere(publicServicePulitzers, {eval(myprop): "The New York Times"});

The error message is SyntaxError: missing : after property id

How can I accomplish this?

Thanks for any help.

解决方案

Just figured it out. The second parameter to findWhere is an object. So create the object first and pass that to the function:

var myprop = 'newsroom';
var value = 'The New York Times';
var search_obj = {};
search_obj[myprop] = value;

var result =  _.findWhere(publicServicePulitzers,search_obj);

Works!

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