why is the error " use of unassigned local variable" ?

Murtaza Hasan

I m a beginner , and in this program i am trying a simple sort . I dont know why i cant print 'sw' in the FOR Loop ?

I want an output :
92
95
97
98
99

Here is my code, please help :

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace ConsoleApplication2

{

class Program

{

static void Main(string[] args)

{

int[] Arr = new int[5] { 99, 98, 92, 97, 95 };

//int[] Arr = { 90, 67, 87, 2, 5 };

int a, b,i;

int kw;

for (i = 0; i < 5; i++)

{

if (Arr[i] > Arr[i + 1])

{

int sw;

sw = Arr[i + 1];

Arr[i + 1] = Arr[i];

Arr[i] = sw;

Console.WriteLine(sw);

}

Console.WriteLine(sw);

// Console.WriteLine(" Sorted Array is : ", sw);

}

Console.ReadLine();

}

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Shweta Lodha12y ago
There are 2 reasons of your error:
1) variable sw if declared inside an IF condition and you are trying to print that variable sw outside IF, which is out of scope.
2) You just declared the variable sw and didn't assigned anything.

So, to resolve the error please declare your variable sw outside IF condition and assign some default value
ashutosh bhardwaj12y ago
int[] Arr = new int[5] { 99, 98, 92, 97, 95 };

//int a, b, i; why declare variables when they are not required?
//int kw;
for (int j = 0; j < 4; j++)
{
for (int i = 0; i < 4; i++)//i<4 instead of i<5 else index gets out of bound since you are comparing i+1
{
if (Arr[i] > Arr[i + 1])
{
int sw;
sw = Arr[i + 1];
Arr[i + 1] = Arr[i];
Arr[i] = sw;
//Console.WriteLine(sw);
}
//Console.WriteLine(sw); sw is a local variable you caanot access it outside the 'if' block
// Console.WriteLine(" Sorted Array is : ", sw);
}
}
for (int i = 0; i < 5; i++)//loop to display the array
Console.WriteLine(Arr[i]);

Console.ReadLine();//hold the output on screen