System out of range exception at the end of the loop

Ram Prasad

System is giving me out of range exception when p = 255. My understading is that with "OR operator, later part of if statement shoudl come into affet. However, it is not. Please advise on how to fix it.

for (int p = 0; p < 256; p++) 
{    
    if (buffer[p] == buffer[p + 1] || buffer[p] == buffer[p - 1])
    {
        //Code
    }
}

7 Replies

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Muhammad Imran Ansari4y ago
You need to check the length of buffer in first condition because buffer[index + 1] and when reach
to last index and after adding 1, code will throw the expected range exception.
In second condition index should not be 0 because you are checking buffer[index-1] and when start from
0 then due to index-1, code will throw the expected range exception. Try the following code:
for (int p = 0; p < 256; p++)
{
      if ((p != (buffer.Length - 1) && buffer[p] == buffer[p + 1]) || (p != 0 && buffer[p] == buffer[p - 1]))
      {
            //Code
      }
}
+1
Nitin Sontakke4y ago
Yes, perfect.

Thanks!
+2
Sachin Singh4y ago
@Nitin Sir, i have said the same thing,
Contion1 Condition2 Resultant
F F F
F T T
T F T
T T T
That code will not execute when both are false, otherwise will execute if anyone is true.
+2
Nitin Sontakke4y ago
Hello Sachin,

I believe OR condition means if either (not both) condition is false....

Please correct me if I am wrong!
+2
Rajanikant Hawaldar4y ago
1. for (int p = 0; p < 256 && (p + 1) !=256; p++)
2. {
3. if (buffer[p] == buffer[p + 1] || buffer[p] == buffer[p - 1])
4. {
5. //Code
6. }
7. }
+2

Rijwan Ansari4y ago

Hi,

Your logic will give this error because you are using p+1 in last loop as well.

Even in or condition, there will be execution.

You can do another check and split into two separate if conditions

Sachin Singh4y ago

'OR' condition means if both conditions are false then the code inside braces will not execute otherwise will execute if any of the condition is true.

here

buffer[p] == buffer[p + 1]
buffer[255] == buffer[256] may give you out of range if buffer[256] is not available.