I know I used the wrong format specifier in my C program when reading floats into int variables using scanf("%f", &variable).
I don't know how the program yields large random values. How do the input values get converted to these random values?
#include <stdio.h>
#include <stdlib.h>
// Width Height --> Floating Point
float findArea (float width, float height)
{
float area;
area = width* height;
printf("width:%f\n",width);
printf("height:%f\n",height);
return area;
}
int main()
{
int heightRectangle, widthRectangle;
float area;
printf("Enter width: ");
scanf("%f",&widthRectangle);
printf("Enter height: ");
scanf("%f", &heightRectangle);
area = findArea(widthRectangle,heightRectangle);
printf("The area of your given rectangle is: %f \n",area);
return 0;
}
Output:
Enter width: 5.0
Enter height: 2.5
width:1084227584.000000
height:1075838976.000000
The area of your given rectangle is: 1166454293721513984.000000
Size of int and float in my system is 4 bytes. I used sizeof operator to determine that.
Compiler Information:
I am using online compiler programiz
Guys, once again I know I used wrong format specifier.I'm just expecting answer which explains how the values 5.0 and 2.5 are getting converted to 1084227584 and 1075838976.
Why this Behaviour? Floating numbers with float data types are encoded using IEEE-754 encoding standard (single precision format).
How does IEEE-754 work in detail?
1.What is IEEE 754?
> It's a standard for how computers represent floating-point numbers. Both positive and negative
floating-point numbers.
2.Single Precision Basics
>Single precision means we use 32 bits (or 4 bytes) to represent a number.
3.The 32 Bits are Split Into Three Parts:
>Sign bit: 1 bit that shows if the number is positive or negative (0 for positive, 1 for negative).
>Exponent: 8 bits that help represent the range of the number.
>Mantissa (or Fraction): 23 bits that hold the actual digits of the number.
4.The Formula for the Number:
>The number is represented as:
[±]1.[mantissa]*2^(exponent-127)
>The exponent is stored with a bias of 127, which helps in handling both small and large numbers.
For more information about single precision format refer this
refer:->iee-754
Explanation:=
width=5.0->101.0 height=2.5->10.1
Single precision conversion of width and height
width=0 10000001 01000000000000000000000
Height=0 10000000 01000000000000000000000
Both int and float data types use 32-bit / 4bytes of computer memory to store data.
These numbers were readed as float but interpreted as integers. Normal integer 32-bit conversion:
Width =01000000101000000000000000000000 is 1084227584
Height=01000000001000000000000000000000 is 1075838976
width*height=1166454293721513984