Chapter 4
A __________ structure can execute a set of statements only under certain circumstances.
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What are the following operators? 1. greater than 2. less than 3. greater than or equal to 4. less than or equal to 5. equal to 6. not equal to
1. > 2. < 3. >= 4. <= 5. == 6. !=
Control structure
a logical design that controls the order in which a set of statements execute
Sequence Structure
a set of statements that execute in the order that they appear
flag
a variable that signals when some condition exists in the program
Conditionally Executed
action that is performed only when a certain condition is true
Compare strings
allows you to create decision structures that test the value of a string
if clause
begins with the word if and is followed by the "condition"
How do we test more than one condition?
by nesting a decision structure inside another decision structure
Decision or Selection structures
can execute a set of statements only under certain circumstances
Relational Operator
determines whether a specific relationship exists between two values
condition
expression that will be evaluated as either true or false
Boolean expression
expressions tested by the if statement
Dual Alternative Decision Structure
has two possible paths of execution one path is taken if the condition is true and another is taken if the condition is false
Example if-elif-else statement
if condition1: statement statement elif condition2: statement statement else: statement statement
Example if-else statement
if condition: statement statement else: statement statement
sample if statement
if condition: statement statement
Single Alternative Decision Structure
provides only one alternative path of execution
What happens when the if statement executes?
the condition is tested if it is true the statements in the block are executed if it is false the statements in the block are skippped
What is used to write a single alternative decision structure?
the if statement
What values can be assigned to a bool variable?
true or false
if statement
used to create a decision structure, which allows a program to have more than one path of execution Causes one or more statements to execute only when a boolean expression is true
nested block
when a block of code that is inside another block of code is indented
if-else statement
will execute one block of statements if its condition is true, or another block if its condition is false