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Select case
The document discusses the problems with using multiple IF statements to handle different conditions for preparing for the weather. It can become confusing and inefficient to add new IF statements for each new condition. The document introduces using a SELECT CASE statement instead, which allows testing multiple conditions at once for a variable, like the weather. This is less confusing, easier to write and modify. An example SELECT CASE statement is provided to test the weather variable and take the appropriate action, like putting on a coat, sunglasses or snow joggers, in a cleaner way than multiple IF statements.
Select case
- 1. SELECT CASE THEFANCY IF
- 2. The Problem WithIF . . . IF it is cold out THEN you will put a coat on ELSE leave the coat at home But what about if it rains! We don’t know what to do! We’re going to have to make another IF statement
- 3. The Problem WithIF . . . IF it is cold out THEN you will put a coat on ELSE leave the coat at home IF its raining THEN you will put a coat on ELSE leave the coat at home But what if its sunny! We’re going to have make another IF statement
- 4. The Problem WithIF . . . IF it is cold out THEN you will put a coat on ELSE leave the coat at home IF its raining THEN you will put a coat on ELSE leave the coat at home IF its sunny THEN go and get you sunglasses ELSE leave the sunglasses at home BUT WHAT IF ITS SNOWING!
- 5. The Problem WithIF . . . IF it is cold out THEN you will put a coat on ELSE leave the coat at home IF its raining THEN you will put a coat on ELSE leave the coat at home IF its sunny THEN go and get you sunglasses ELSE leave the sunglasses at home IF its snowing THEN go put on your snow joggers ELSE leave the snow joggers at home This isn’t very efficient! Plus its confusing
- 6. Select Case ToThe Rescue! • Select case is like IF but allows you to test many things at once in one construct • This is – less confusing – Easier to type up – Easier to modify
- 7. Select Case ToThe Rescue! In Select case, a variable is tested using a criteria. Case: Cold or Case: Sunny? raining? Get your Get your coat sunglasses on! Case: Snow? Get your snow Weather joggers on
- 8. Select Case inVB Select Case WEATHER Case cold, raining put your coat on! Case sunny put your sunglasses on Case snow put your snow joggers on End Select