C while showing two times before stop - c

Question

This is the called Function:
int onBattle(int level,char nomeheroi[20])
{
const char *monsternames[4][3] = {
{"Rat","Bat","Spider"},
{"Goblin","Orc","Dwarf"},
{"Dragon","Lich","Banshee"},
{"Demon","Hydra","Giant Spider"}
};
//printf("monster hp:%f , player hp:%f, player name:%s ",globalvar.monterhp, globalvar.playerhp,nomeheroi);
char opcaobattle;
rndMonster(level);
while((globalvar.monterhp > 0) || (globalvar.playerhp > 0)){
printf("Monster name:%s\n",monsternames[globalvar.monstercatego][globalvar.monsternivel]);
printf("Monster Life:%f\n",globalvar.monterhp);
printf("------------------------------------------\n");
printf("----------------BattleGround--------------\n");
printf("------------------------------------------\n");
printf("Player name:%s\n", nomeheroi);
printf("Player life:%f\n", globalvar.playerhp);
printf("----------------------------------------\n");
printf("------------------Menu------------------\n");
printf("----------------------------------------\n");
printf("A - Attack\n");
printf("D - Defend\n");
scanf("%c",&opcaobattle);
switch(opcaobattle)
{
case 'a':
danoPMonster();
break;
case 'd':
break;
}
}
if(globalvar.monterhp <= 0)
{
return 0;
}
else if(globalvar.playerhp <= 0)
{
return 1;
}
}
This is what happen:
I dont any problem with this code to show two times before stop on Scanf, i tried Do While too and the same thing happens any help?
ps: that globalvar is a global struct and yes there is a value

Answer 1

scanf("%c",&opcaobattle);
I suggest adding a space to the conversion specifier to make sure it isn't using a left-over newline character in the stream.
scanf(" %c",&opcaobattle);
It might be good to have a default case for the switch, too:
default:
printf("Please enter one of the available commands.\n");