Say I have List<string> FontStyle containing the following
"a0.png",
"b0.png",
"b1.png",
"b2.png",
"b3.png",
"c0.png",
"c1.png",
"d0.png",
"d1.png",
"d2.png"
I want to randomly select a string from the list with its first character matches a certain character. For example if the character is c. The method will returns either c0.png or c1.png randomly.
How do I do this using LINQ?
This should do the trick:
var random = new Random();
var list = new List<string> {
"a0.png",
"b0.png",
"b1.png",
"b2.png",
"b3.png",
"c0.png",
"c1.png",
"d0.png",
"d1.png",
"d2.png"
};
var startingChar = "d";
var filteredList = list.Where(s => s.StartsWith(startingChar)).ToList();
Console.WriteLine(filteredList.Count);
int index = random.Next(filteredList.Count);
Console.WriteLine(index);
var font = filteredList[index];
Console.WriteLine(font);
but the problem with the entire solution is that the smaller the resulting filtered list is the less likely you are to get really random values. The Random class works much better on much larger constraints - so just keep that in mind.
Where instead of Select in the first line
IEnumerable<T>. Needs ToList() on the first line.
ScriptCs. Absolutely fantastic!Random random = ...;
var itemsStartingWithC = input
.Where(x => x.StartsWith("c"))
.ToList();
var randomItemStartingWithC =
itemsStartingWithC.ElementAt(random.Next(0, itemsStartingWithC.Count()));
The call to ToList isn't strictly necessary, but results in faster code in this instance. Without it, Count() will fully enumerate and ElementAt will need to enumerate to the randomly selected index.
char from each string, that start from c?ElementAt but typed Select. Corrected.
funcx.Count will return the length of the substring, while you are using it inside ElementAt. You need to access Count on a filtered list