[maxpower1991]

can I use if statement in said switch ???
in this code :

main(){
int z;
while(z!=3)
{
cout<<"\n...............MENU.................\n\n";
cout<<"Enter.....(1)\n";
cout<<"Enter.....(2)\n";
cout<<"Enter.....(3)\n";
cin>>z;
switch(z)
{
//some statement.......
} 

break;
case 2:
{
//some statement.......
} 

break;
}}

and I don't want to enter 2 unless enter 1
???

help please and thanks

[Korupt]

With switch:

switch(z)
{
	case 1:
		//Option 1
	break;

	case 2:
		//Option 2
	break;

	case 3:
		//Option 3
	break;

	default:
		//None of the options
	break;
}

With if:

if (z == 1)
{
	//Option 1
}
else if (z == 2)
{
	//Option 2
}
else if (z == 3)
{
	//Option 3
}
else
{
	//None of the options
}

This post has been edited by Korupt: 28 May 2010 - 01:01 PM

[Aphex19]

I dont really get what you are trying to ask. Can you clarify?

[maxpower1991]

Aphex19, on 28 May 2010 - 07:25 PM, said:

I dont really get what you are trying to ask. Can you clarify?

I don't want the user to get inside case 2: case 3: case 4: and so on
before Enter case 1:

because every thing depend on case 1:

what the way can I use to do that?

[Kilorn]

Sounds like you don't need a switch at all, sounds to me like all you need are nested if checks

if (blah > 0)
{
    if (blah > 3)
    {
        if (blah > 4)
        {
            // do something...
        }
    }
    else if (blah > 2)
    {
        // do something...
    }
}

Unless I'm completely misunderstanding your question, as far as I know, there isn't a way to allow a switch to work the way you're describing.

Or another way could be to have an if check before the switch, and have the switch inside the if check, then the switch wouldn't be accessed unless a specific thing were true.

if (blah > 3)
{
    switch(blah)
    {
        case 0:
            // do something...
            break;
        case 1:
            // do something different...
            break;
        default:
            break;
    }
}

This post has been edited by Kilorn: 28 May 2010 - 02:15 PM

[maxpower1991]

Kilorn, on 28 May 2010 - 08:11 PM, said:

Sounds like you don't need a switch at all, sounds to me like all you need are nested if checks

if (blah > 0)
{
    if (blah > 3)
    {
        if (blah > 4)
        {
            // do something...
        }
    }
    else if (blah > 2)
    {
        // do something...
    }
}

Unless I'm completely misunderstanding your question, as far as I know, there isn't a way to allow a switch to work the way you're describing.

Or another way could be to have an if check before the switch, and have the switch inside the if check, then the switch wouldn't be accessed unless a specific thing were true.

if (blah > 3)
{
    switch(blah)
    {
        case 0:
            // do something...
            break;
        case 1:
            // do something different...
            break;
        default:
            break;
    }
}

thank you so so so so much
you give me an idea to solve my problem
thank u

[jjl]

why not just use a boolean to flag if the user has already entered one?

[IngeniousHax]

Or you can have it default to one, and fall through to 2, 3, 4 by omitting the break; statement after case 1... probably terrible practice but would work.

[BlueMelon]

You could use a BOOL value.

bool 1_IsPicked = false;

main(){
int z;
while(z!=3)
{
cout<<"\n...............MENU.................\n\n";
cout<<"Enter.....(1)\n";
cout<<"Enter.....(2)\n";
cout<<"Enter.....(3)\n";
cin>>z;
switch(z)
{

case 1:
{
1_IsPicked = true;
// Some stuff
}
break;

case 2:
{
if(1_IsPicked == true)
{
// Do your stuff
}
}
break;
} 
}

This post has been edited by BlueMelon: 29 May 2010 - 04:56 PM

[sarmanu]

Variable names can't start with numbers, BlueMelon.

[BlueMelon]

It was meant for an example, sarmanu.

This post has been edited by BlueMelon: 30 May 2010 - 06:24 AM

[sarmanu]

I knew you would say that. When you provide an example, at least use valid syntax. Otherwise, show him pseudocode.

[DarkX411]

Wouldn't switch only be useful if you're using a big list, cause doesn't use nested if-else's get a little inefficient after awhile?

[jjl]

well heres another example by just checking the conditions

int menu(void)
{
	int input;
	cout<<"\n...............MENU.................\n\n";
	cout<<"Enter.....(1)\n";
	cout<<"Enter.....(2)\n";
	cout<<"Enter.....(3)\n";
	cout<<"QUIT......(4)\n";
	cin>>input;
	return input;
}

int main()
{
	int choice = 0;
	while((choice = menu())!=1) { cerr<<"You must select 1 first!"<<endl; }
	
	do{
		switch(choice)
		{
		case 1: cout<<"SELECTED 1"<<endl; break;
		case 2: cout<<"SELECTED 2"<<endl; break;
		case 3: cout<<"SELECTED 3"<<endl; break;
		default: cout<<"INPUT ERROR"<<endl;
		}
		
	}while((choice = menu())!=4);

	return 0;
}

This post has been edited by ImaSexy: 30 May 2010 - 02:21 PM