**1. Cyclic nature of unsigned char:**

Consider following c program:

**#include**<stdio.h>

**void**

**main**(){

**unsigned**

**char**c1=260;

**unsigned**

**char**c2=-6;

printf("%d %d",c1,c2);

}

Output: 4 250 (why?)

This situation is known as overflow of unsigned
char.

Range of unsigned char is 0 to 255. If we
will assign a value greater than 255 then value of variable will be changed to
a value if we will move clockwise direction as shown in the figure according to
number. If number is less than 0 then we have to move in anti clockwise
direction.

**Short cut formula to find cyclic value:**

**If number is X where X is greater than 255 then**

**New value = X % 256**

**If number is Y where Y is less than 0 then**

**New value = 256 – (Y% 256)**

2. Cyclic nature of signed

2. Cyclic nature of signed

**char:**

**#include**<stdio.h>

**int**

**main**(){

**signed**

**char**c1=130;

**signed**

**char**c2=-130;

printf("%d %d",c1,c2);

**return**0;

}

Output: -126
126 (why?)

This situation is known as overflow of signed char.

Range of unsigned char is -128 to 127. If we
will assign a value greater than 127 then value of variable will be changed to
a value if we will move clockwise direction as shown in the figure according to
number. If we will assign a number which is less than -128 then we have to move
in anti clockwise direction.

**Shortcut formula to find cyclic value:**

**If number is X where X is greater than 127 then**

**p = X % 256**

**if p <=127**

**New value = p**

**else**

**New value = p – 256**

**If number is Y where Y is less than -128 then**

**p = Y % 256**

**If p <= 127**

**New value = -p**

**else**

**New value = 256 -p**

Overflow of char data type in c programming

Overflow of int data type in c programming

Overflow of long int data type in c programming

Overflow of float data type in c programming

## 5 comments:

#include

int main()

{

signed char c=-128;

printf("%d ",c);

return 0;

}

what is the value of c?

-128 :D

char c = 250;

c+=8;

What is the value of c?

250+8 is 258 so 3 more than 255.

If we move 3 more places it gives us the answer 2.

2

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