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Converting Switch to If/elese

gamesir (3)
Hey guys, I'm just going over some practice problems for my introductory C++ class and I'm struggling with finding a solution to converting this switch code to an if/else statement. I don't have the book yet(broke), so it's really hard trying to find a solution

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int x, y, z;
		cout << “Enter 3 values: “;
		cin >> x >> y >> z;
		switch (y) {
			case 2: 	switch (x) {
					case 4: cout << y << endl;
						break;
					case 5: cout << z << endl;
				}
				break;
			case 3:  switch (z) {
					case 2: cout << x + y << endl;
					break;
				}
				break;
			default:  cout << “I’m Done” << endl;
		}


I'd appreciate just a general pointer please
elite zero (106)
See a switch statement as such:

Switch (y) = If (y)

then each case is == ?.

So, 
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switch (y) {
			case 2: 	switch (x) {
					case 4: cout << y << endl;
						break;
					case 5: cout << z << endl;
				}
				break;


Is,
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If (y == 2) 
{
		switch (x)   // Same here
                       {
					case 4: cout << y << endl;
						break;
					case 5: cout << z << endl;
				}
				break;


gamesir (3)
Never knew you could use If/Switch. The instruction say if/else.
I'm struggling to understand the purpose and function of this code as well.
The user inputs 3 numbers, which are assigned to x,y,z in that order.
Then the program is aying if y meets whatever condition(I don't know what it is), then it does what?
Output that same number?
gamesir (3)
bump
Disch (13742)
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if(a == 1)
{
    xxx;
}
else if(a == 2)
{
    yyy;
}
else
{
    zzz;
}


Is the same as:

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switch(a)
{
case 1:
    xxx;
    break;

case 2:
    yyy;
    break;

default:
    zzz;
    break;
}
Chervil (7320)
Never knew you could use If/Switch. The instruction say if/else.

No, that's not quite what was meant.

An if statement looks like this:
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if (condition)
    statement1;
else
    statement2;


Now statement1 and statement2 can be as simple or as complex as you like. If necessary, it could be a block of several lines of code enclosed in braces { }.

It just happens that
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switch (variable)
{
    // case statements etc.
}
is a block of code which is regarded as a single statement, thus that entire structure can be dropped into place instead of statement1 or statement2
newbieg (764)
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switch(variable)
{
     case 1:
          variable = 2; //Code to run if variable == 1 ...
          break;  //break ends the switch statement immediately
                  //if you don't break the switch continues testing all other cases, 
                  //if we didn't break now, case 2: would have immediately run.

     case 2:
          //Code you want to run if variable == 2
          break;

     default:
          //Code to run if no other cases tested as true
          break;
}


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if(variable == 1)
{
 //code you want to run if variable == 1

}
else if(newVariable == 2)
{
  //this code will run if newVariable is equal to 2
  //also this code only runs if the argument in the previous if() tested as false.
}
else if(variable == 3)
{
  //all previous arguments tested as false, but this is true.
}
else //no parenthesis
{
  //this runs if all other if's and else if's were false (much like the default: in a switch)
}


So pretty much the idea is that else if()'s are easier to use in shorter tests, or if you need to test multiple variables (also look into using AND(&&) OR(||) ). Switch/case is used when there are a lot of possible answers for a single variable.
Last edited on
elite zero (106)
Exactly
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