How to display more digits when printing a double?

Question

calculating the square root of a number

#include<iostream>
#include<math.h>

using namespace std;
int main()
{ 
double pmid=0,n,st=0,en,mid=0;
double dif=3;
cin>> n;               // number whose square root is to be found
en=n;                 // end number    
while(dif>.00000001){
mid =(st+en)/2;       //mid number , st = start number 
if (mid*mid>n){       
    en=mid;          // re positioning end number 
}
else {
    st =mid;          // re positioning end number 
}

dif=fabs(pmid-mid);   //difference between previous and present mid values 
pmid=mid;
cout  <<mid<<" "<<dif<< endl;
}
}

output image

the problem in my results and the results in calculator are different I calculated output of the number 10 as 3.16228 and the google calculator calculates it as 3.16227766017 I think my written code rounds off the value and displays it . How can I get the values as shown by calculator.

you want to know how to display more digits? Your title says something else — 463035818_is_not_an_ai, Feb 18 '17 at 17:38
Check the [c++ standard I/O manipulators](http://en.cppreference.com/w/cpp/io/manip) facilities. — πάντα ῥεῖ, Feb 18 '17 at 17:42

score 2 · Answer 1 · answered Feb 18 '17 at 17:50

2

I don't know if there is another solution but I know that this will work:

cout << setprecision(10);

Run this before you print out your double.

You can set the number to whatever you want but cout << 1.22222222222222222222; will still only print out 1.2222222222222223 since you went over the precision limit of the double.

answered Feb 18 '17 at 17:50

Nicola Uetz

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it rounds off the variable.1.22222222222222222222 will be shown as 1.2222222222222223 I want to see only 5 values after decimal – Bogorovich Feb 18 '17 at 18:19
So you change setprecision() to 5. Simple as that. – BusyProgrammer Feb 18 '17 at 21:48
@ABusyProgrammer `cout << setprecision(5); cout<<1.222299;` will give `1.2223` I want it to be `1.2222` – Bogorovich Feb 19 '17 at 04:51
What you need in that case is `std::floor` search it up on google; lots of help on how to implement it will come up. – BusyProgrammer Feb 19 '17 at 04:54

How to display more digits when printing a double?

1 Answers1