textwidth() function
textwidth function returns the width of a string in pixels.
Declaration of textwidth() function
int textwidth(char *string);C programming source code for textwidth()
#include<graphics.h>
#include<conio.h>
main()
{
int gd = DETECT, gm, width;
char array[100];
initgraph(&gd, &gm, "C:\\TC\\BG I");
width = textwidth("C programming");
sprintf(array,"Textwidth = %d",width);
outtext(array);
getch();
closegraph();
return 0;
}