C++ Problem I get â€œnanâ€ as output everytime I run my program

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I was required to create a program with a function that changes height in feet to height in meters. I made the function and when I cout from the function I get the right value but when I cout it in main I get "nan". I dont understand why the value is not printing. This is my first time using this website so I am sorry if I miss anything.

#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;


double heightInMeters(double feet , double inches)

double footToMeter = 0.305;
double inchToMeter = 0.0254;

double heightInMeters = ((footToMeter * feet) + (inchToMeter * inches));
cout << heightInMeters << endl;



int main()


double feet, inches, calcheight;
char ch;

cout << "Enter your height [Use format ft-in]: ";
cin >> feet >> ch >> inches;

calcheight = heightInMeters(feet, inches);
cout << calcheight << endl;

return 0;

asked 2 hours ago

Khizar Muhammad

363

New contributor

Possible duplicate of function keeps returning NaN
â€“Â Julien Lopez
56 mins ago

add a commentÂ |Â

up vote
6
down vote

favorite

#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;


double heightInMeters(double feet , double inches)

double footToMeter = 0.305;
double inchToMeter = 0.0254;

double heightInMeters = ((footToMeter * feet) + (inchToMeter * inches));
cout << heightInMeters << endl;



int main()


double feet, inches, calcheight;
char ch;

cout << "Enter your height [Use format ft-in]: ";
cin >> feet >> ch >> inches;

calcheight = heightInMeters(feet, inches);
cout << calcheight << endl;

return 0;

asked 2 hours ago

Khizar Muhammad

363

New contributor

Possible duplicate of function keeps returning NaN
â€“Â Julien Lopez
56 mins ago

add a commentÂ |Â

up vote
6
down vote

favorite

#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;


double heightInMeters(double feet , double inches)

double footToMeter = 0.305;
double inchToMeter = 0.0254;

double heightInMeters = ((footToMeter * feet) + (inchToMeter * inches));
cout << heightInMeters << endl;



int main()


double feet, inches, calcheight;
char ch;

cout << "Enter your height [Use format ft-in]: ";
cin >> feet >> ch >> inches;

calcheight = heightInMeters(feet, inches);
cout << calcheight << endl;

return 0;

asked 2 hours ago

Khizar Muhammad

363

New contributor

#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;


double heightInMeters(double feet , double inches)

double footToMeter = 0.305;
double inchToMeter = 0.0254;

double heightInMeters = ((footToMeter * feet) + (inchToMeter * inches));
cout << heightInMeters << endl;



int main()


double feet, inches, calcheight;
char ch;

cout << "Enter your height [Use format ft-in]: ";
cin >> feet >> ch >> inches;

calcheight = heightInMeters(feet, inches);
cout << calcheight << endl;

return 0;

c++ function nan

asked 2 hours ago

Khizar Muhammad

363

New contributor

asked 2 hours ago

Khizar Muhammad

363

New contributor

asked 2 hours ago

Khizar Muhammad

363

New contributor

asked 2 hours ago

Khizar Muhammad

363

asked 2 hours ago

Khizar Muhammad

363

New contributor

Khizar Muhammad is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

Possible duplicate of function keeps returning NaN
â€“Â Julien Lopez
56 mins ago

add a commentÂ |Â

Possible duplicate of function keeps returning NaN
â€“Â Julien Lopez
56 mins ago

Possible duplicate of function keeps returning NaN
â€“Â Julien Lopez
56 mins ago

add a commentÂ |Â

3 Answers
3

active

oldest

votes

up vote
6
down vote

accepted

This function here:

double heightInMeters(double feet , double inches)

 double footToMeter = 0.305;
 double inchToMeter = 0.0254;

 double heightInMeters = ((footToMeter * feet) + (inchToMeter * inches));
 cout << heightInMeters << endl;

isn't returning anything. That's undefined behavior, what you get here

calcheight = heightInMeters(feet, inches);

Is most likely just some invalid rubbish value then. Perhaps instead of this:

cout << heightInMeters << endl;

You wanted this:

return heightInMeters;

Does your compiler issue any warnings for your code? If not, please try to find out if you can set it to give you more warnings. Most compilers usually complain about missing returns.

answered 1 hour ago

Blaze

1,744218

1

Thank you so much, your answer helped alot!
â€“Â Khizar Muhammad
1 hour ago

1

No problem, glad it helped.
â€“Â Blaze
1 hour ago

add a commentÂ |Â

up vote
3
down vote

heightInMeters doesn't have an explicit return value.

Therefore, since it's not a void function (or main), the behaviour of your program is undefined.

Didn't your compiler warn you of that? It's an easy spot for a compiler to make in your case, and the current crop of compilers all warn if you turn the warning level up appropriately.

(Granted, NaN is a peculiar manifestation of that undefined behaviour.)

Finally, note that one foot is exactly 0.3048 meters. Base your conversion metrics from that. Your values introduce unnecessary imprecision.

edited 30 mins ago

answered 1 hour ago

Bathsheba

170k26239363

While that is certainly an issue, I doubt the NaN return is due to that. More likely his cin is reading garbabe to begin with.
â€“Â Zinki
1 hour ago

@Zinki: It's plausible in a debug build, I guess?
â€“Â Bathsheba
1 hour ago

Thank you, I added a return and it worked! My compiler didnt warn me. I am using code blocks.
â€“Â Khizar Muhammad
1 hour ago

@KhizarMuhammad: Your last job is to fix the conversion constants; they are inadequate particularly given that you're using a double. I'd recode so you only had one constant if I were you.
â€“Â Bathsheba
1 hour ago

add a commentÂ |Â

up vote
1
down vote

void f()

 double a=0.3;
 cout << a << endl;

//
// inside main function 
f();

double f()

 double a=0.3;
 return aÃ¯Â¼Â›


// inside main function 
cout << f() << endl;

Because the return value of your code is not specified, the output is Ã¢Â€ÂœnanÃ¢Â€Âœ

edited 29 mins ago

Pretasoc

563214

answered 52 mins ago

Rong Wu

112

New contributor

add a commentÂ |Â

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3 Answers
3

active

oldest

votes

3 Answers
3

active

oldest

votes

up vote
6
down vote

accepted

This function here:

double heightInMeters(double feet , double inches)

 double footToMeter = 0.305;
 double inchToMeter = 0.0254;

 double heightInMeters = ((footToMeter * feet) + (inchToMeter * inches));
 cout << heightInMeters << endl;

isn't returning anything. That's undefined behavior, what you get here

calcheight = heightInMeters(feet, inches);

Is most likely just some invalid rubbish value then. Perhaps instead of this:

cout << heightInMeters << endl;

You wanted this:

return heightInMeters;

Does your compiler issue any warnings for your code? If not, please try to find out if you can set it to give you more warnings. Most compilers usually complain about missing returns.

answered 1 hour ago

Blaze

1,744218

1

Thank you so much, your answer helped alot!
â€“Â Khizar Muhammad
1 hour ago

1

No problem, glad it helped.
â€“Â Blaze
1 hour ago

add a commentÂ |Â

up vote
6
down vote

accepted

This function here:

double heightInMeters(double feet , double inches)

 double footToMeter = 0.305;
 double inchToMeter = 0.0254;

 double heightInMeters = ((footToMeter * feet) + (inchToMeter * inches));
 cout << heightInMeters << endl;

isn't returning anything. That's undefined behavior, what you get here

calcheight = heightInMeters(feet, inches);

Is most likely just some invalid rubbish value then. Perhaps instead of this:

cout << heightInMeters << endl;

You wanted this:

return heightInMeters;

Does your compiler issue any warnings for your code? If not, please try to find out if you can set it to give you more warnings. Most compilers usually complain about missing returns.

answered 1 hour ago

Blaze

1,744218

1

Thank you so much, your answer helped alot!
â€“Â Khizar Muhammad
1 hour ago

1

No problem, glad it helped.
â€“Â Blaze
1 hour ago

add a commentÂ |Â

up vote
6
down vote

accepted

This function here:

double heightInMeters(double feet , double inches)

 double footToMeter = 0.305;
 double inchToMeter = 0.0254;

 double heightInMeters = ((footToMeter * feet) + (inchToMeter * inches));
 cout << heightInMeters << endl;

isn't returning anything. That's undefined behavior, what you get here

calcheight = heightInMeters(feet, inches);

Is most likely just some invalid rubbish value then. Perhaps instead of this:

cout << heightInMeters << endl;

You wanted this:

return heightInMeters;

Does your compiler issue any warnings for your code? If not, please try to find out if you can set it to give you more warnings. Most compilers usually complain about missing returns.

answered 1 hour ago

Blaze

1,744218

This function here:

double heightInMeters(double feet , double inches)

 double footToMeter = 0.305;
 double inchToMeter = 0.0254;

 double heightInMeters = ((footToMeter * feet) + (inchToMeter * inches));
 cout << heightInMeters << endl;

isn't returning anything. That's undefined behavior, what you get here

calcheight = heightInMeters(feet, inches);

Is most likely just some invalid rubbish value then. Perhaps instead of this:

cout << heightInMeters << endl;

You wanted this:

return heightInMeters;

Does your compiler issue any warnings for your code? If not, please try to find out if you can set it to give you more warnings. Most compilers usually complain about missing returns.

answered 1 hour ago

Blaze

1,744218

answered 1 hour ago

Blaze

1,744218

answered 1 hour ago

Blaze

1,744218

answered 1 hour ago

Blaze

1,744218

1

Thank you so much, your answer helped alot!
â€“Â Khizar Muhammad
1 hour ago

1

No problem, glad it helped.
â€“Â Blaze
1 hour ago

add a commentÂ |Â

1

Thank you so much, your answer helped alot!
â€“Â Khizar Muhammad
1 hour ago

1

No problem, glad it helped.
â€“Â Blaze
1 hour ago

Thank you so much, your answer helped alot!
â€“Â Khizar Muhammad
1 hour ago

No problem, glad it helped.
â€“Â Blaze
1 hour ago

add a commentÂ |Â

up vote
3
down vote

heightInMeters doesn't have an explicit return value.

Therefore, since it's not a void function (or main), the behaviour of your program is undefined.

Didn't your compiler warn you of that? It's an easy spot for a compiler to make in your case, and the current crop of compilers all warn if you turn the warning level up appropriately.

(Granted, NaN is a peculiar manifestation of that undefined behaviour.)

Finally, note that one foot is exactly 0.3048 meters. Base your conversion metrics from that. Your values introduce unnecessary imprecision.

edited 30 mins ago

answered 1 hour ago

Bathsheba

170k26239363

While that is certainly an issue, I doubt the NaN return is due to that. More likely his cin is reading garbabe to begin with.
â€“Â Zinki
1 hour ago

@Zinki: It's plausible in a debug build, I guess?
â€“Â Bathsheba
1 hour ago

Thank you, I added a return and it worked! My compiler didnt warn me. I am using code blocks.
â€“Â Khizar Muhammad
1 hour ago

@KhizarMuhammad: Your last job is to fix the conversion constants; they are inadequate particularly given that you're using a double. I'd recode so you only had one constant if I were you.
â€“Â Bathsheba
1 hour ago

add a commentÂ |Â

up vote
3
down vote

heightInMeters doesn't have an explicit return value.

Therefore, since it's not a void function (or main), the behaviour of your program is undefined.

Didn't your compiler warn you of that? It's an easy spot for a compiler to make in your case, and the current crop of compilers all warn if you turn the warning level up appropriately.

(Granted, NaN is a peculiar manifestation of that undefined behaviour.)

Finally, note that one foot is exactly 0.3048 meters. Base your conversion metrics from that. Your values introduce unnecessary imprecision.

edited 30 mins ago

answered 1 hour ago

Bathsheba

170k26239363

While that is certainly an issue, I doubt the NaN return is due to that. More likely his cin is reading garbabe to begin with.
â€“Â Zinki
1 hour ago

@Zinki: It's plausible in a debug build, I guess?
â€“Â Bathsheba
1 hour ago

Thank you, I added a return and it worked! My compiler didnt warn me. I am using code blocks.
â€“Â Khizar Muhammad
1 hour ago

@KhizarMuhammad: Your last job is to fix the conversion constants; they are inadequate particularly given that you're using a double. I'd recode so you only had one constant if I were you.
â€“Â Bathsheba
1 hour ago

add a commentÂ |Â

up vote
3
down vote

heightInMeters doesn't have an explicit return value.

Therefore, since it's not a void function (or main), the behaviour of your program is undefined.

Didn't your compiler warn you of that? It's an easy spot for a compiler to make in your case, and the current crop of compilers all warn if you turn the warning level up appropriately.

(Granted, NaN is a peculiar manifestation of that undefined behaviour.)

Finally, note that one foot is exactly 0.3048 meters. Base your conversion metrics from that. Your values introduce unnecessary imprecision.

edited 30 mins ago

answered 1 hour ago

Bathsheba

170k26239363

heightInMeters doesn't have an explicit return value.

Therefore, since it's not a void function (or main), the behaviour of your program is undefined.

Didn't your compiler warn you of that? It's an easy spot for a compiler to make in your case, and the current crop of compilers all warn if you turn the warning level up appropriately.

(Granted, NaN is a peculiar manifestation of that undefined behaviour.)

Finally, note that one foot is exactly 0.3048 meters. Base your conversion metrics from that. Your values introduce unnecessary imprecision.

edited 30 mins ago

answered 1 hour ago

Bathsheba

170k26239363

edited 30 mins ago

answered 1 hour ago

Bathsheba

170k26239363

answered 1 hour ago

Bathsheba

170k26239363

answered 1 hour ago

Bathsheba

170k26239363

While that is certainly an issue, I doubt the NaN return is due to that. More likely his cin is reading garbabe to begin with.
â€“Â Zinki
1 hour ago

@Zinki: It's plausible in a debug build, I guess?
â€“Â Bathsheba
1 hour ago

Thank you, I added a return and it worked! My compiler didnt warn me. I am using code blocks.
â€“Â Khizar Muhammad
1 hour ago

@KhizarMuhammad: Your last job is to fix the conversion constants; they are inadequate particularly given that you're using a double. I'd recode so you only had one constant if I were you.
â€“Â Bathsheba
1 hour ago

add a commentÂ |Â

While that is certainly an issue, I doubt the NaN return is due to that. More likely his cin is reading garbabe to begin with.
â€“Â Zinki
1 hour ago

@Zinki: It's plausible in a debug build, I guess?
â€“Â Bathsheba
1 hour ago

Thank you, I added a return and it worked! My compiler didnt warn me. I am using code blocks.
â€“Â Khizar Muhammad
1 hour ago

@KhizarMuhammad: Your last job is to fix the conversion constants; they are inadequate particularly given that you're using a double. I'd recode so you only had one constant if I were you.
â€“Â Bathsheba
1 hour ago

While that is certainly an issue, I doubt the NaN return is due to that. More likely his cin is reading garbabe to begin with.
â€“Â Zinki
1 hour ago

@Zinki: It's plausible in a debug build, I guess?
â€“Â Bathsheba
1 hour ago

Thank you, I added a return and it worked! My compiler didnt warn me. I am using code blocks.
â€“Â Khizar Muhammad
1 hour ago

@KhizarMuhammad: Your last job is to fix the conversion constants; they are inadequate particularly given that you're using a double. I'd recode so you only had one constant if I were you.
â€“Â Bathsheba
1 hour ago

add a commentÂ |Â

up vote
1
down vote

void f()

 double a=0.3;
 cout << a << endl;

//
// inside main function 
f();

double f()

 double a=0.3;
 return aÃ¯Â¼Â›


// inside main function 
cout << f() << endl;

Because the return value of your code is not specified, the output is Ã¢Â€ÂœnanÃ¢Â€Âœ

edited 29 mins ago

Pretasoc

563214

answered 52 mins ago

Rong Wu

112

New contributor

add a commentÂ |Â

up vote
1
down vote

void f()

 double a=0.3;
 cout << a << endl;

//
// inside main function 
f();

double f()

 double a=0.3;
 return aÃ¯Â¼Â›


// inside main function 
cout << f() << endl;

Because the return value of your code is not specified, the output is Ã¢Â€ÂœnanÃ¢Â€Âœ

edited 29 mins ago

Pretasoc

563214

answered 52 mins ago

Rong Wu

112

New contributor

add a commentÂ |Â

up vote
1
down vote

void f()

 double a=0.3;
 cout << a << endl;

//
// inside main function 
f();

double f()

 double a=0.3;
 return aÃ¯Â¼Â›


// inside main function 
cout << f() << endl;

Because the return value of your code is not specified, the output is Ã¢Â€ÂœnanÃ¢Â€Âœ

edited 29 mins ago

Pretasoc

563214

answered 52 mins ago

Rong Wu

112

New contributor

void f()

 double a=0.3;
 cout << a << endl;

//
// inside main function 
f();

double f()

 double a=0.3;
 return aÃ¯Â¼Â›


// inside main function 
cout << f() << endl;

Because the return value of your code is not specified, the output is Ã¢Â€ÂœnanÃ¢Â€Âœ

edited 29 mins ago

Pretasoc

563214

answered 52 mins ago

Rong Wu

112

New contributor

edited 29 mins ago

Pretasoc

563214

edited 29 mins ago

Pretasoc

563214

edited 29 mins ago

Pretasoc

563214

answered 52 mins ago

Rong Wu

112

New contributor

answered 52 mins ago

Rong Wu

112

answered 52 mins ago

Rong Wu

112

New contributor

Rong Wu is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

add a commentÂ |Â

Khizar Muhammad is a new contributor. Be nice, and check out our Code of Conduct.

draft saved

draft discarded

Khizar Muhammad is a new contributor. Be nice, and check out our Code of Conduct.

draft saved

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