What went wrong with this program....?

Question

1.00/5 (1 vote)

See more:

#define PI (22/7)
#include<stdio.h>
void main()
{
	float x,y;
	x=PI;
	y=22/7;
    printf("\nx=%f y=%f",x,y);
}

I'm expecting an output as follows x=3.148, y=3.148
but it's as follows
x=3.000000 y=3.000000

What I have tried:

I have used gcc compiler to compile the above code.

Posted 6-Jun-17 7:15am

ArvindSai

Updated 6-Jun-17 8:47am

jeron1

v3

Add a Solution

Comments

ZurdoDev 6-Jun-17 13:23pm

I have not done C in a long, long time but I think you can do either 22.0/7.0 or 22f/7f. They are being treated as integers.

Kornfeld Eliyahu Peter 6-Jun-17 13:43pm

Sorry - I didn't saw your comment (refresh maybe?) but it is truly yours...

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Kornfeld Eliyahu Peter · Answer 1 · 2017-06-06T07:39:00

The problem with your numbers (the constants 22 and 7). The compiler interprets them as integers and therefore performs an integer division (it means that the result an integer too)...
So actually 22/7 is compiled to (int)((int)22 / (int)7), that results in 3...
You have free ways to overcome it...
1. Add one place after the decimal point (a ) of course to keep the value) - 22 => 22.0. This will force the compiler to interpret the number as double...
2. Add a suffix too to create a float - 22 => 22.0f...
3. Store values in variables an use them in division -

C++

float f22 = 22; 
float f7 = 7; 
float x = f22 / f7;

Patrice T · Answer 2 · 2017-06-06T08:47:00

Quote:
What went wrong with this program....?

Simple, this is C behavior.
The C compiler look at 22 and 7, both are integers, so the compiler decide to do an integer division.
To ensure the division will be floating point, the literal must be floating point too.
The compiler knows a literal is a floating point when it encounter a '.'
22 and 7 are integers, 22.0 and 7.0 are same value but floating point.
22/7 => 3
22.0/7.0=> 3.14....

What went wrong with this program....?

2 solutions

Solution 1

Solution 2

Add your solution here

Preview 0