# Outline for April 17, 2014

Reading: text, § 5, 7
Due: April 17, 2014
1. Why you don’t count with floating point numbers [roundoff.py]
2. Simultaneous assignment [swap.py]
1. Simple assignment: variable = expression
2. Simultaneous assignment: variableA, variableB = expressionA, expressionB
3. Decision structures
1. If statement [if0.py]
2. Executes once, based on condition
3. Syntax
4. Conditions
1. Resolves to boolean value
2. Literal booleans: True (1), False (0)
3. Relational operators
1. Use two arithmetic expressions connected with relational operatorsto create a boolean
2. Relational operators: >, >=, <, <=, ==, \lstinline/!=/
3. Precedence: resolved after arithmetic operators
4. Connectives: and, or, not
5. 6 > 2 + 3; "UCD" == "Sac State"
5. Two-way decisions [if1.py]
1. if-else statements
2. One condition, two possible code blocks
3. else very powerful when the positive condition is easy to describe but not the negative
6. Multi-way decisions [if2.py]
1. Can execute code based on several conditions
2. elif (else if)
3. else only reached if all previous conditions false
4. Nested if statements
7. Indefinite loops: execute until a general condition is false (while)
1. while [while.py]
2. Contrast with for
3. break causes program to fall out of loop (works with for too) [loop1.py]
4. continue causes program to start loop over immediately (works with for too) [loop1.py]
8. Definite loops: execute a specific (definite) number of times (for)
1. General form: for i in iterator
2. Iterator is either list or something that generates a list
3. Very common form: for i in range(1, 10)
9. range() in detail [for.py]
1. range(10) gives 0 1 2 3 4 5 6 7 8 9
2. range(3, 10) gives 3 4 5 6 7 8 9
3. range(2, 10, 3) gives 2 5 8
4. range(10, 2, -3) gives 10 7 4
10. Program: counting to 10 [toten.py]
11. Program: sum the first 10 squares [sumsq.py]

 You can also obtain a PDF version of this. Version of April 16, 2014 at 10:59PM