Flowchart 1r4m6

Chapter 3 Flowchart

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Outline • By the end of this chapter, you will be able to: – Solve a given problem by applying flowchart – Understand control structures

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Flowchart • Visual representation of each task and how the tasks will flow to produce a full program. • Shows the program logic as each task is represented by certain symbols, which are then connected by lines and arrows to show the flow.

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Flowchart symbols Symbol Terminal

Input / Output

Purpose Your flowchart should always begin and end with this symbol. It indicates the starting or ending point of the logic. It symbolizes input (Read / Prompt / Get) or output (Print / Write / Put / Output / Display) process in a pseudocode. 4

Flowchart symbols Symbolizes any process in Process a pseudocode. Declaring variables, calculations and asg values are some examples of a process. This symbol indicates that Predefined there is a module in an process algorithm. In other words, the module can be expended to include few sub processes. 5

Flowchart symbols This is used when there are Decision decisions to be made in the logic. When this symbol is used, there will be options where the logic needs to decide which path to take. Flow lines are used to Flow lines connect the various symbols that you will use in drawing your flowchart. It indicates the logic flow of control. 6

Control structures • There are 3 basic control structures: – Sequential – Selection – Repetition

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Sequential • Straightforward execution. Process one step after another • Basic computer operations 1. 2. 3. 4.

Receive information Put out information Perform arithmetic Assign values

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How do you boil water on stove?

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Add 2 numbers START

1. Start 2. Declare variables, number_1, number_2, total 3. total = number_1 + number_2 4. Display total 5. End

Declare variables number_1,number_2,t otal Get number_1,number_ 2 total=number_1+num ber_2 Display total

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Selection • Condition: based on the condition criteria, certain actions will be executed and some will not • Condition can either be: true or false

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Example • Say for example you are trying to decide whether to go watch a movie in Ipoh. However, the weather is a factor of concern for you. If it rains, you decide to finish up your assignment. If it does not rain, you will go to watch movie.

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Flowchart

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Repetition • Allows tasks to be done repeatedly which can be controlled by setting certain condition • When condition is false, the repetition stops and the tasks will not be executed

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Example • I would like to add sugar into my cup of coffee. However, that would depend on how sweet it will taste after each additional spoon of sugar.

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Flowchart Start

Not Sweet?

FALSE

TRUE Add Sugar

End

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Note • Pseudocode and flowchart for repetition and looping will be learnt in more detail later the semester.

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