const char*str;
for(i=0;i<4;i++){
if(slot[i]){
str=strcat("P",(char*)i);
}
}
strcat(str,"Are Free")
you cannot write a c string to a pointer, you need a buffer big enough to accept all of the chars:
char str[SOME_BIG_ENOUGH_SIZE];
for(i=0;i<4;i++){
if(slot[i]){
//str=strcat("P",(char*)i); don't know what you are trying to do there
}
}
strcat(str,"Are Free"); // appends str with the literal "Are Free"