[Resolved] if, else, else if

Barb54

Can someone please explain the differences between
just plain if by itself, then
if
else

if
else if

I need to learn the proper usage of each.

Thanks,
Barb

drawmack

An example:

Let's say you want to drink coffee if it is morning, but you don't care about anything else then:

if (morning) {drink coffee;}

Now let's say that if it is morning you want to drink coffee but any other time you want to drink juice

if (morning) {drink coffee;}
else {drink juice;}

Now let's say that if it is morning you want to drink coffee, if it is night you want to drink tea, but you don't care about anything else then:

if(morning) {Drink coffee;}
elseif(night) {drink tea;}

Now for the last one. Let's say if it is morning you wnat to drink coffee, if it is afternoon you want to drink tea, if it is any other time you want to drink beer then:
if(morning) {drink coffee;}
elseif(afternoon) {drink tea;}
else {drink beer;}

Barb54

Sorry, but this forum and another one are my "classrooms" for php/mysql, lol.

Ok, so if I had a form to post points to create new records for my members and I have several different types of points - then the actual points for the types are in their own tables - I could possibly do something like this?

I have a "type" table and 4 "points" tables, I want the form to be used to insert data into a "records" table

something like this:
if type = A connect to point1 table, put data in array, then display that array as a dropdown list for user to choose the appropriate point
elseif type = B use point2 table, same thing
elseif type = C use point 3 table, same thing
else use point4 table (which would be the one used most often)

I learned Structured Cobol many many years ago and we approached conditional statements from the negative.

I don't want the code to waste it's time going thru the IF's so if the most likely selection is point4 table, should that be in the first if? If condition 1 is true I want it to process the data and not run thru the other IF's.

Also would this possibly need to be a multipage form?

Thanks,
Barb

drawmack

that is correct however, if you're doing a bunch of conditions on one variable then a switch statement is better (http://www.php.net/switch)

broc7

If you're testing the same value more than 2 or 3 times, you're better off using the switch statement.

switch(type) {
 case "D":
  $table="point4";
  break;
 case "C":
  $table="point3";
  break;
 case "B":
  $table="point2";
  break;
 default:
  $table="point1";
}

With switch, it's better to put the most frequent option first since php will exit switch at the first break. On the other hand, if point4 in this example is used for many different types, instead of just "D", it's better in the default position, since this will catch anything not tested for.

broc7

Oops, too late.

Barb54

Wow, I have seen some case statements mixed with functions and using the break but I thought that was just used with Smarty LOL. That's how much I DON"T know yet, lmbo.

It's a perfectly logical route to take I think. I will do some more research on functions, switches, case to see how I can incorporate these into my overall design.

Right now, I just want to get my first form(applications form) working with some checks on the fields and I will be happy. As for the point form, I am using 4 different forms now with NO checks, lol, but they each work. The trick will be to combine them into one form if possible and set up the code so that others can easily use it for their sites as well.

You've given me a lot to think about. THANKS!

Barb