How to convert a floating point to a string in C/C ++

Recently, when writing a program, you need to convert a floating point number to a string, especially when you execute SQL, you can search for sprintf_s from the Internet, but I did not try it successfully.

Later, we found that the following two methods can be used to convert a floating point to a string:

Two functions can be used to convert a floating point number to a string: _ gcvt and _ gcvt_s. The latter is an enhanced version. The two functions need the header file: # include
<Stdlib. h>.

For example:

Char carray1 [20];

Char carray2 [20];

Char carray3 [20];

Double nresult = 1.0/3.0;

_ Gcvt_s (carray1, nresult, 10); // format 1, retain 10 after decimal point

Printf ("nresult = % s \ n", carray1 );

// Format 2. Parameter 2 specifies the size of the string array, with 10 digits after the decimal point

_ Gcvt_s (carray2, 20, nresult, 10 );

Printf ("nresult = % s \ n", carray2 );

_ Gcvt (nresult, 12, carray3); // keep 12 digits after the decimal point

Printf ("nresult = % s \ n", carray3 );

Note: The 2nd parameters of these two functions indicate that the number of digits after the decimal point is retained. Therefore, the _ gcvt ratio _ gcvt_s in the above example outputs two more parameters.

We recommend that you use the second form of _ gcvt_s for better security.