Tutorial 4 Decision Making with Control Structures and Statements Section A - Decision Making JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

Tutorial 4A Topics Section A - Decision Making if statements if…else statements Nested if statements switch statements JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

Decision Making Decision Making Process of determining the order in which statements execute in a program AKA – flow control Decision-Making Structures Special type of JavaScript statements used for making decisions JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

Decision Making if Statements Used to execute specific programming code if the evaluation of a conditional expression returns a value of true “Do this or don’t do this” Syntax (3 primary parts) if (conditional_expression) { statement(s); } JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

Decision Making if Statements Operation Command block If the conditional expression is true, the statement(s) is/are executed Control then continues to subsequent code Command block Multiple statements contained within a set of braces (require curly braces) JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

Decision Making if Statements Conditional Expression Can consist of: Comparison operators Logical operators Combination of the two Must resolve to Boolean value JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

Decision Making if…else Statements Used to execute one set of code if the evaluation of a conditional expression returns a value of true, otherwise executes another set of code “Do this or do something else” Syntax if (conditional_expression) { statement(s); } else { } JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

Decision Making Nested if and if…else Statements Nested statements Statements contained within other statements Syntax (variable) if (conditional_expression) { statement(s); } } else { JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

Decision Making switch Statements Controls program flow by executing a specific set of statements, depending on the value of an expression Syntax switch (expression) { case label1: statement(s); break; case label2: default: } JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

Decision Making switch Statements Case labels Break statement Identify specific code segments Can use a variety of data types as case labels Break statement Used to exit switch statements Default label Contains statements that execute when the condition expression doesn’t match any of the case labels JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

JavaScript Tutorial 4 -Decision Making with Control Structures and Statements

JavaScript Tutorial 4 -Decision Making with Control Structures and Statements