how to get all non null values from array in c#

Question

i'm printing all non null values from array which contain null values. i want to print only non null values

string a = "welcome";

var rm = new string [] {null,"hai",null,"15"};

Console.WriteLine("{0}",!String.IsNullOrEmpty(rm[0])? a 
:!String.IsNullOrEmpty(rm[1]) ? a +":"+ rm[1] : 
!String.IsNullOrEmpty(rm[2]) ? a +":"+ rm[1]+ ":"+rm[2] : a +":"+ rm[1]+ 
":"+rm[2]+":"+rm[3] );

actual output : welcome:hai

Expected output : welcome:hai:15

`using System.Linq; var filtered = rm.Where( elem => ! string.IsNullOrEmpty(elem))` to filter to what you want to print, then use string.Join. — Patrick Artner, Aug 12 '19 at 08:04
are you looking specifically for a linq solution? have you tried using a loop ? — Mong Zhu, Aug 12 '19 at 08:05
@AgentFire the separator comes first, then the collection ;) — Mong Zhu, Aug 12 '19 at 08:06

score 3 · Accepted Answer · answered Aug 12 '19 at 08:11

You can get and IEnumerable representing all non-null and non-empty values by using the Where method.

Your array is called rm so you could get the IEnumerable like this:

IEnumerable<string> nonNullNonEmptyValues = rm.Where(e => !String.IsNullOrEmpty(e));

If you want to join them like in your example you can use String.Join like this (@AgentFire has an error in his comment since this method actually takes the separator first, then the values):

String joined = String.Join(":", nonNullNonEmptyValues);

score 3 · Answer 2 · answered Aug 12 '19 at 08:12

3

If you want using a loop, it will your solution:

string a = "welcome";

var rm = new string [] {null,"hai",null,"15"};
for(int i = 0; i < rm.Length; i++)
{
  if(!string.IsNullOrWhitespace(rm[i])
    a += ":" + rm[i];
}
Console.WriteLine(a);

answered Aug 12 '19 at 08:12

chesh111re

184
2
11

how to get all non null values from array in c#

2 Answers2