I have a method in my controller util file that parses through some strings to find matches I need to pass in a multidimensional array. When I call this method in various controllers how in Apex do instantiate a
List<List<String>>
Util class has this:
public static Boolean hasPreference(List<List<String>> preferenceMatches){
[code that parses is in here, not relevant to my question]
}
You could prepare a script for your understanding.
prepare the array
List<List<String>> preferenceMatchesList = new List<List<String>();
for(Integer n=0;n<3;n++)
{
List<String> lstStr = new List<String>();
for(Integer i=0; i<5;i++)
{
lstStr.add('Value' + n + i);
}
preferenceMatchesList.add(lstStr);
}
System.debug(preferenceMatchesList);
DEBUG|preferenceMatches=((Value00, Value01, Value02, Value03, Value04), (Value10, Value11, Value12, Value13, Value14), (Value20, Value21, Value22, Value23, Value24))
pass the array to the method
if (hasPreference(preferenceMatchesList))
{
//do something
}
You pass the parameter just like you'd pass any other parameter.
That is, if you have a variable such as List<List<String>> myMultidimensionalStringList, your method call would be
Util.hasPreference(myMultidimensionalStringList);
I don't think that's what you're actually asking about though. If I had to take a guess, I'd guess that your actual question is how to get data into such a variable in the first place.
There are a few different ways you could approach this, which I'll illustrate below.
// The thing to realize in all of these examples is that the outermost level
// is a List of Lists.
// This is a bit different from the multidimensional arrays in C++, for example.
// Instead of simply adding values directly to the List<List<String>> at your target
// indices, you'll need to store your values in lists, and then add those lists
// to your List<List>.
// First, using curly braces to initialize a list directly.
// I wouldn't recommend doing this directly in a method call
myMultidimensionalStringList = new List<List<String>>{
new List<String>{'a', 'b', 'c'},
new List<String>{'1', '2', '3'},
new List<String>{'foo', 'bar', 'baz'}
};
// Second, adding empty lists to the outermost list, and then adding values
myMultidimensionalStringList = new List<List<String>>();
// You can use the curly brace initialization here too
myMultidimensionalStringList.add(new List<String>{'a', 'b', 'c'});
// ...or add a completely empty list and populate values as you go
myMultidimensionalStringList.add(new List<String>());
myMultidimensionalStringList[1].add('1');
myMultidimensionalStringList[1].add('2');
myMultidimensionalStringList[1].add('3');
// Third, using loops, which cuts down on the amount of code you have to write
List<String> tempList;
for(MyObject__c myObj :[<some query here>]){
tempList = new List<String>();
tempList.add(myObj.someField__c);
tempList.add(myObj.someOtherField__c);
myMultidimensionalStringList.add(tempList);
}
List<List<String>>, please edit your question to reflect that. If that isn't it, some additional explanation of what exactly you're stuck on would be helpful.