How to convert a number to a string in this language?

label- & gt; Text = trackBar- & gt; Value;

Answer 1, authority 100%

Unfortunately, there is no normal standard way of converting numbers to strings in C++ 2003. Possible solutions:

1. sprintf – C-style solution

2. itoa is another C-style option. Not a standard feature, but many implementations do.

3. stringstream :

   stringstream ss;
   int i = 777;
   ss & lt; & lt; i;
   string str = ss.str ();
   

4. boost :: lexical_cast

5. For more complex conversions, you can use boost :: format

C++ 11 finally has normal conversion functions, including std :: to_string , overloaded for different numeric types. Works fine in g ++ – 4.7.

Answer 2, authority 25%

atoi (); from stdlib.h

Answer 3, authority 25%

@Fangog , he was surprised to find that in addition to sprintf () there is nothing standard. If needed, here is a function for different number systems. Binary to hexadecimal common digits. For the rest (up to 64-bit), the character set is from base64 (RFC1113).

You might be surprised, but printf in Windows (at least 32-bit XP) does not work correctly with multiple arguments if there is a long long (64-bit integer) among them.

Faced with this fact, I wrote a transform function (well, and generalized it a bit).
If you find it useful, take it.

/ *
 llstr.c avp 2011, 2012
 Convert long-long fixed integer (64-bit) to string in the specified radix
 (any 2..64 (bin, octal, decimal, hex ...))
 Returns string length.
 * /
#ifdef TEST
#include & lt; stdio.h & gt;
#include & lt; stdlib.h & gt;
#include & lt; string.h & gt;
#endif
int
my_llstr (long long v, // source for 'printing'
   int radix,
   int unsign, // if 1 then unsigned source
   char * res) // memory for result
{
 const char * dig = "0123456789abcdef";
 static const char cb64 [] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 + /";
 int rem [65], sp = 0; // stack for reminders
 char * p = res; // for return length
 unsigned long long u = v; // use if unsign == 1
 if (! res)
  return 0;
 if (radix & lt; 2)
  radix = 2;
 if (radix & gt; 64)
  radix = 64;
 if (radix & gt; 16)
  dig = cb64;
 if (unsign) {
  while (u & gt; = radix) {
   rem [sp ++] = u% radix;
   u = u / radix;
  }
  * res ++ = dig [u];
 } else {
  if (v & lt; 0) {
   * res ++ = '-';
   v = -v;
  }
  while (v & gt; = radix) {
   rem [sp ++] = v% radix;
   v = v / radix;
  }
  * res ++ = dig [v];
 }
 while (sp)
  * res ++ = dig [rem [- sp]];
 * res = 0;
 return res-p;
}
#ifdef TEST
main (int ac, char * av [])
{
 long x;
 int n;
 char buf [100];
 int r = av [1]? atoi (av [1]): 10;
 while (scanf ("% ld", & amp; x) == 1) {
  n = my_llstr (x, r, 0, buf);
  printf ("% s \ n", buf);
 }
}
#endif

Answer 4

Since C++ 11, the language has a function to_string :

int n = 1;
std :: string str = std :: to_string (n);