what is the point of setting 'speed=a' in the 4th line of this code instead if just directly using 'int speed' in the parentheses of the 'setcarspeed' (3rd line) function?

Question

class myClass {
public:
void setcarspeed (int a){
speed=a;
}
int getcarspeed(){
return speed;
}
private:
int speed;
};

int main() {
myClass obj;
obj.setcarspeed (40);
cout<<obj.getcarspeed ;

return 0;
}

Answer 1

int a is the parameter of the setcarspeed() function and will only be used inside that function. Same would apply for int speed if you'd use it as a parameter. Speed = a uses the value of your parameter a and makes your class member speed use it for everything that you desire in the instance of your object obj