I have a list as a single string like - "['2','4','5','1']" and length of this is 17 as each char is counted.
Now I want to parse it into list object like - ['2','4','5','1'] whose length will be 4 as the number of elements in a list.
How can I do this in C#?
Can it be done without doing basic string operations? If yes then how?
Without basing string operations
Your string value looks like valid JSON array.
using Newtonsoft.Json;
var list = JsonConvert.DeserializeObject<List<char>>("['2','4','5','1']");
// => ['2','4','5','1']
If you need output as integers set output type to be list of integers and JSON serializer will convert it to integers.
var list = JsonConvert.DeserializeObject<List<int>>("['2','4','5','1']");
// => [2, 4, 5, 1]
Converting to integers will handle negative values as well ;)
var list = JsonConvert.DeserializeObject<List<int>>("['-2','4','-5','1']");
// => [-2, 4, -5, 1]
You can try regular expressions and Linq in order to Match all the integers and turn them (ToList()) into List<int>:
using System.Linq;
using System.Text.RegularExpressions;
...
string str = "['2','4','5','1']";
var result = Regex
.Matches(str, @"\-?[0-9]+") // \-? for negative numbers
.Cast<Match>()
.Select(match => int.Parse(match.Value)) // int.Parse if you want int, not string
.ToList();
Try to Split by , and then use Regex to get only digits:
var str = "['2','4','5','1']".Split(new char[] {',' })
.Select(s => Regex.Match(s, @"\d+").Value);
Or thanks to @Fildor :
var str = Regex.Matches("['2','4','5','1']", @"\d+").Cast<Match>()
.Select(s=> s.Value);
list = Newtonsoft.Json.JsonConvert.DeserializeObject<List<char>>("['2','4','5','1']");var result = str.Split(',','[',']').Where(s => !string.IsNullOrEmpty(s)).ToList();StringSplitOptions.RemoveEmptyEntries- don't know if there's a difference in performance, but I'd rather use the option.var result = str.Split(new[] { ',','[',']' }, StringSplitOptions.RemoveEmptyEntries);