Basic Conditions

1
Basic Conditions
2
Challenge

• Ask the user his/her name
• If its Wally, jeer him
• Pause video and try on your own.

3
Conditional Branching

• Allows the computer to make decisions
• Based on a condition
• Embedded into some other programming structure

4
Condition

• Expression
• Can be evaluated to true or false
• Often compares a variable to a value
• Sometimes compares two variables

5
Comparison Operators

• Equals
• ! Not Equal
• lt Less than or equal to
• gt Greater than or equal to
• lt Less than
• gt Greater than

6
If Statement

• Checks a condition
• Begins a block of code
• If condition is true, executes all code in block
• If condition is false, skips code block

7
If example

• If its raining
• Wear a raincoat
• End if

8
Challenge Algorithm

• New program hiWally by me
• New variable userName string starts with
• Ask users name, store in userName
• If userName is equal to Wally
• Output You Bovine
• End if
• End Program

9
Challenge

• Modify the Wally program so it says one thing if
  the users name is Wally, and a more benign
  greeting if its someone else
• Pause video and try on your own

10
Using an Else Clause

• Else is a useful addition to If statements.
• Else allows you to set up another block of code
  to execute if the condition is false

11
If-Else Example

• If its raining
• Wear a raincoat
• Else
• Wear a sweater
• End if

12
Challenge Algorithm

• New program wallyOrNot by me
• New variable userName string starts with
• Ask users name, store in userName
• If userName is equal to Wally
• Output You Bovine
• Else
• Output Do I know you userName ?
• End if
• End Program

13
(No Transcript)
14
Challenge Algorithm
15
(No Transcript)
16
Code

• My code