[SalesForce] List of IDs from List

I have a List of sObjects (User) and need to put the ID of each record in this List into a separate List of type String.

I found this related question and answer, but this puts the ID into a Set (I need it into a List) – the code from this that's not working is below.

List<User> users = [SELECT Id, Name, ContactId FROM User];
List<String> userIds = (new Map<Id,User>(users)).keySet();

Thanks in advance for your assistance.

Best Answer

Apex lists have a constructor that takes a set as an argument to you can do this to end up with a list rather than a set:

List<Id> userIds = new List<Id>(new Map<Id, User>(users).keySet());

(This also relies on this convenience map constructor.)

Note that although you can use the string type for ID values, it is clearer to use the ID class and that also allows ID-specific methods to be invoked.

Related Solutions

[SalesForce] Can you filter a list from a SOQL query in apex doing something like LINQ in .NET

There is no equivalent of LINQ in Apex (how I wish there was), so you're right your two options are:

One big query, which you then "filter" in Apex code. I'd recommend using a for loop to iterate over every case and storing them in a Map<String, List<Case>> keyed by Status which you can then expose to your Visualforce page from your controller.
Multiple smaller queries with the results for each stored in a separate List<Case> exposed to your controller.

The first method is the preferred one, since as you rightly it reduces the number of SOQL queries that need to be performed.

You can then access the map in your apex:repeat like this:

<apex:repeat value="{!yourmap['key']}" var="listvalue">
    ...
</apex:repeat>

[SalesForce] Access sObject list variables in Javascript

There is no need to use the apex:repeat. You can use the resulting records as string more directly.

What you have is a JSON serialized representation of your apex structure - that is a list of wrapper objects.

There is a javascript method called JSON.parse() to convert the string into an object - or an array of objects in your case:

var json = '{!accountWrapperList }';
var records = JSON.parse(json);

Now you should have something usable right here

console.log(records);

And also this should work as expected

console.log(records[0].check);

Best Answer

Related Solutions

[SalesForce] Can you filter a list from a SOQL query in apex doing something like LINQ in .NET

[SalesForce] Access sObject list variables in Javascript

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