explicit type casting float(intvar) results in int

Question

I tried the following code :

#include <iostream>
#include<conio.h>
using namespace std;
int main()
{
    int intvar = 25;
    float floatvar = 35.87;
    cout << "intvar= " << intvar;
    cout << "\n floatvar =" << floatvar;
    cout << "\n float(intvar)=" << float(intvar);
    cout << "\n int(floatvar)=" << int(floatvar);
    _getch();
    return 0;
}

The result for float(intvar) is coming as 25.
Can someone please explain why it is still being shown as an integer and not 25.000000?

Because they mean the same? And how exactly you chose the number of zeroes? Anyway, this may be helpful, if you want to format the output: http://stackoverflow.com/questions/11989374/floating-point-format-for-stdostream/11989420#11989420 — Kiril Kirov, Jun 19 '15 at 07:12

score 3 · Answer 1 · answered Jun 19 '15 at 07:16

3

The value is not an integer, it's just that std::cout will try to give you a compact representation here. Use setfixed and setprecision (from #include <iomanip>) to force a specific output precision on floats. Add this before the first cout line:

cout << fixed << setprecision(6);

answered Jun 19 '15 at 07:16

filmor

30,840
6
50
48

I had the doubt because i expected float to print a decimal no. And not just an integer. But thank u, will try ur suggestion :) – user2549980 Jun 20 '15 at 14:34

score 0 · Answer 2 · edited Jun 20 '20 at 09:12

You need to specify the format for floatingPoint output, such as:

cout << "\n float(intvar)=" << std::fixed << float(intvar);

From [The.C++.Programming.Language.Special.Edition] 21.4.3 FloatingPoint Output [io.out.float]:

Floatingpoint output is controlled by a format and a precision:

– The general format lets the implementation choose a format that presents a value in the style that best preserves the value in the space available. The precision specifies the maximum number of digits. It corresponds to printf()’s %g (§21.8).

– The scientific format presents a value with one digit before a decimal point and an exponent. The precision specifies the maximum number of digits after the decimal point. It corresponds to printf()’s %e .

– The fixed format presents a value as an integer part followed by a decimal point and a fractional part. The precision specifies the maximum number of digits after the decimal point. It corresponds to printf()’s %f .

explicit type casting float(intvar) results in int

2 Answers2