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CPG101 Java Programming

Lesson 5: Program Flow

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Lesson 5: Program FlowObjectives

To write Selection statements

To write Iteration statements

Programming Exercises

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Selection Statements

Based on the user input, decision making will takeplace.

It involves choosing between two alternative

courses of action.

Java supports two kinds of selection statements

The if, if..else or nested ifstatement

The switch statement

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The ifstructure

A single-alternate ifas it only performs an action

based on one alternative.

Theif..else

structure A dual-alternate ifas it requires two options for the

next course of action.

Performs one action when a boolean expression

evaluates as true and another when the booleanexpression evaluates as false.

Selection Statements

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Iteration Statements

A structure that allows a block of statements to beexecuted repeatedly depending on the evaluation

of the boolean expression.

A loop that never ends is called a endless loop or

infinite loop.

A loop within a loop is called a nested loop.

Java supports three kinds of iteration statements

The while loop The do..while loop

Theforloop

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The while loop Used to repeat a statement or block only if the

condition is true.

The do..while loop

Used when we need to execute the loop body at least

once before checking the condition.

like the while loop, it will only repeat a statement or

block if the condition is true.

Iteration Statements

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The testing of the condition is placed differently while loop test the condition first, then execute the

body of statements.

do.. while execute the body of statements before

testing the condition.

Iteration Statements

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Theforloop

Allows the statements in the loop body to be

executed a specific number of times.

Iteration Statements

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Programming Exercises

Write a Java program to capture the users name and age

and display a message based on the following information:

if age > 65 display retired

if age is between 22 to 65 display working

if age is between 7 to 21 display studying

if age < 7 display playing

The user will be prompted to enter another name and age.

If the user decides not to enter another name, theprogram will terminate.

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The End