通过值查找javascript中对象的索引 [英] Find index of object in javascript by a value

问题描述

我在json中有很长的时区列表，如下所示.

I have a long list of timezones in json like the following.

[
 {"value": "Pacific/Niue", "name": "(GMT-11:00) Niue"},
 {"value": "Pacific/Pago_Pago", "name": "(GMT-11:00) Pago Pago"},
 {"value": "Pacific/Honolulu", "name": "(GMT-10:00) Hawaii Time"},
 {"value": "Pacific/Rarotonga", "name": "(GMT-10:00) Rarotonga"},
 {"value": "Pacific/Tahiti", "name": "(GMT-10:00) Tahiti"},
 {"value": "Pacific/Marquesas", "name": "(GMT-09:30) Marquesas"},
 {"value": "America/Anchorage", "name": "(GMT-09:00) Alaska Time"},
 {"value": "Pacific/Gambier", "name": "(GMT-09:00) Gambier"},
 {"value": "America/Los_Angeles", "name": "(GMT-08:00) Pacific Time"},
 {"value": "America/Tijuana", "name": "(GMT-08:00) Pacific Time -  Tijuana"},
 {"value": "America/Vancouver", "name": "(GMT-08:00) Pacific Time - Vancouver"},
]

我设置了用户时区检测功能，该功能返回的时区字符串为"America/Los_Angeles"

I have user timezone detection set up which returns a timezone string as "America/Los_Angeles"

使用Java语言，我想找到json对象中America/Los_Angeles的位置，因此我可以使用其名称"来预填充表单字段.

Using Javascript I want to find the where America/Los_Angeles is in the json object so I can use its "name" to prefill a form field.

我对indexOf()方法很熟悉，但是无法弄清楚在这种情况下如何使用它.有没有一种简单的方法可以解决这个问题，或者我应该只遍历整个列表?

I am familiar with indexOf() method, but can't work out how to use it in this situation. Is there a simple way to handle this or should I just foreach through the whole list?

推荐答案

使用Java语言，我想找到America/Los_Angeles所在的位置 json对象，以便我可以使用其名称"来预填充表单字段.

Using Javascript I want to find the where America/Los_Angeles is in the json object so I can use its "name" to prefill a form field.

您可以使用findIndex

var index = arr.findIndex( s => s.value == "America/Los_Angeles" )

，现在使用此索引来预填充一个字段.

and now use this index to prefill a field.

或者简单地使用find返回对象

Or simply use find to return an object

var element = arr.find( s => s.value == "America/Los_Angeles" )

并在element本身中设置名称字段

and set the name field in the element itself

element.name = "somevalue";

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