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OVERFLOW IN C

Char overflow in c

1. Cyclic nature of unsigned char:

Consider following c program:#includevoidmain(){

unsignedchar c1=260;unsignedchar 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:

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If number is X where X is greater than 255 thenNew value = X % 256

If number is Y where Y is less than 0 then

New value = 256 (Y% 256)2. Cyclic nature of signed char:#includeintmain(){

signedchar c1=130;signedchar 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.

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Shortcut formula to find cyclic value:

If number is X where X is greater than 127 then

p = X % 256

if p

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Short cut formula to find cyclic value:

If number is X where X is greater than 65535 thenNew value = X % 65536If number is Y where Y is less than 0 then

New value = 65536 (Y% 65536)4. Cyclic nature of signed int:

Range of unsigned int is -32768 to 32767. If we will

assign a value greater than 32767 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 that number is

less than -32768 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 32767 thenp = X % 65536if p

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p = Y % 65536

If p

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double data type overflow :

For example: What will be output of following c

code?#includeint main(){

float pmax= 3.5e38f;float nmin=-3.3e38f;float min= 1.0e-38f;

printf("%f %f %f",pmax,nmin,min);return 0;

}

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