Coit29222 structured programming lecture week 06
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COIT29222-Structured Programming Lecture Week 06. Reading: Study Guide Book 2, Modules 9 & 10 Textbook (4 th Ed.), Chapter 2 Textbook (6 th Ed.), Chapters 4 & 5 This week, we will cover the following topics: More on Selection -switch statement -selection (ternary) operators

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COIT29222-Structured Programming Lecture Week 06

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Coit29222 structured programming lecture week 06

COIT29222-Structured Programming Lecture Week 06

  • Reading: Study Guide Book 2, Modules 9 & 10

    Textbook (4th Ed.), Chapter 2

    Textbook (6th Ed.), Chapters 4 & 5

  • This week, we will cover the following topics:

    • More on Selection

      -switch statement

      -selection (ternary) operators

    • More on Loops

      -while vs. do-while

      -for vs. while

      -nested loops


Selection statements

Selection statements

  • We have been using one C++ selection statement – if-else.

  • In this class we explore other selection statements – statements that allow us to perform different tasks, depending on the input data.

    • switch statement

    • ternary operators


If else a review

if-else – a review

  • Let’s start out by reviewing what we know about the if-else statement.

    if statement

    if (Age < 18)

    {

    cout<<“A child!“<<endl;

    }

    if-else statement

    if (Age < 18)

    {

    cout<<“A child!“<<endl;

    }

    else

    {

    cout<<“An adult!“<<endl;

    }


Coit29222 structured programming lecture week 06

if-else-if statement

if (Age < 13)

{

cout<<“A child!“<<endl;

}

else if ((Age >= 13 ) && (Age <= 17))

{

cout<<“A teenager!“<<endl;

}

else

{

cout<<“An adult!“<<endl;

}


Coit29222 structured programming lecture week 06

Braces

  • if (Age < 13)

  • cout<<“A child!“<<endl;

  • else if ((Age >= 13 ) && (Age <= 17))

  • cout<<“A teenager!“<<endl;

  • else

  • cout<<“An adult!“<<endl;

  • Braces are not required if branch has only one statement.

  • We recommend you always use braces in this course.

  • Sometimes we omit them to fit our examples on a slide.


Nested if else

Nested if/else

if (Gender==‘M’)

if (Age < 18)

cout<<“Amale child!“<<endl;

else

cout<<“A man!“<<endl;

else

if (Age < 18)

cout<<“Afemale child!“<<endl;

else

cout<<“A woman!“<<endl;


Nested if else1

Nested if/else

if (Gender==‘M’)

if (Age < 18)

cout<<“Amale child!“<<endl;

else

cout<<“A man!“<<endl;

else if (Gender==‘F’)

if (Age < 18)

cout<<“Afemale child!“<<endl;

else

cout<<“A woman!“<<endl;

else

cout<<“Unknown gender!“<<endl;


Other selection statements

Other selection statements

  • Selection statements allow us to perform different tasks in our programs, depending on the input data.

  • The if-else statement is the only selection statement we need. However, most programming languages provide other selection statement for convenience.

  • In C++, the switch statement is an alternative to the if-else-if statement

  • For example, a menu-driven program might start like this...


Other selection statements1

Other selection statements

Data Processing Application

===========================

Select from the menu below:

1 – Load input data from disk

2 – Enter input data

3 – Save input data to disk

4 – Process input data

5 – Display output data

6 – Clear input data

0 – Exit

Enter your selection ==> 2

:

The main function of this program may include the following if-else-if statement...


Coit29222 structured programming lecture week 06

int MenuSelection = 1;

while (MenuSelection != 0)

{

DisplayMenuAndObtainSelection( MenuSelection );

if ( MenuSelection== 1 )

LoadInputDataFromDisk( InputData );

else if ( MenuSelection== 1 )

EnterInputData( InputData );

else if ( MenuSelection== 3 )

SaveInputDataToDisk( InputData );

else if ( MenuSelection== 4 )

ProcessInputData( InputData, OutputData );

else if ( MenuSelection== 5 )

DisplayOutputData( OutputData );

else if ( MenuSelection== 6 )

ClearInputData( InputData );

else if ( MenuSelection!= 0 )

cout << ”Invalid menu selection!";

}

functions

Or, we can use a switch statement...


Coit29222 structured programming lecture week 06

notes: a little easier to read than if-else-if

int MenuSelection = 1;

while (MenuSelection != 0)

{

DisplayMenuAndObtainSelection( MenuSelection );

switch ( MenuSelection )

{

case 1: LoadInputDataFromDisk( InputData );

break;

case 2:EnterInputData( InputData );

break;

case 3: SaveInputDataToDisk( InputData );

break;

case 4: ProcessInputData( InputData, OutputData );

break;

case 5: DisplayOutputData( OutputData );

break;

case 6: ClearInputData( InputData );

break;

case 0: break;

default: cout << ”Unknown menu selection!";

}

}


Coit29222 structured programming lecture week 06

notes: on break jump to end of switch statement

int MenuSelection = 1;

while (MenuSelection != 0)

{

DisplayMenuAndObtainSelection( MenuSelection );

switch ( MenuSelection )

{

case 1: LoadInputDataFromDisk( InputData );

break;

case 2:EnterInputData( InputData );

break;

case 3: SaveInputDataToDisk( InputData );

break;

case 4: ProcessInputData( InputData, OutputData );

break;

case 5: DisplayOutputData( OutputData );

break;

case 6: ClearInputData( InputData );

break;

case 0: break;

default: cout << ”Unknown menu selection!";

}

}


Coit29222 structured programming lecture week 06

notes: default handles cases not handled above

int MenuSelection = 1;

while (MenuSelection != 0)

{

DisplayMenuAndObtainSelection( MenuSelection );

switch ( MenuSelection )

{

case 1: LoadInputDataFromDisk( InputData );

break;

case 2:EnterInputData( InputData );

break;

case 3: SaveInputDataToDisk( InputData );

break;

case 4: ProcessInputData( InputData, OutputData );

break;

case 5: DisplayOutputData( OutputData );

break;

case 6: ClearInputData( InputData );

break;

case 0: break;

default: cout << ”Unknown menu selection!";

}

}


The s witch statement

The switch statement

  • switch is a convenient replacement for simple if-else-if statements

  • However, switch can only be used when the selection depends on the value of a variable of type integer or char (characters are stored as an integer, using ASCII coding system)

    switch ( <integer or char variable> )

    {...}


The s witch statement1

The switch statement

or, more fully…

switch (<integer or char variable> )

{

case < constant or literal integer or char >:

< statements to handle this case>

break;

:

< other cases >

:

default:

< statements to handle cases not handled above>

}

notes: must be a variable of type integer or char


The s witch statement2

The switch statement

or, more fully…

switch (<integer or char variable> )

{

case < constant or literal integer or char >:

< statements to handle this case>

break;

:

< other cases >

:

default:

< statements to handle cases not handled above>

}

notes: integer or char literal or constant – eg: 1, 'A', EXIT


The s witch statement3

The switch statement

or, more fully…

switch (<integer or char variable> )

{

case < constant or literal integer or char >:

< statements to handle this case>

break;

:

< other cases >

:

default:

< statements to handle cases not handled above>

}

notes: don’t forget the colon


The s witch statement4

The switch statement

or, more fully…

switch (<integer or char variable> )

{

case < constant or literal integer or char >:

< statements to handle this case>

break;

:

< other cases >

:

default:

< statements to handle cases not handled above>

}

notes: break; is optional


Optional break

Optional break;?

switch ( CharMenuSelection )

{

case 'a':

case 'A':

ProcessSelectionA;

break;

case 'b':

case 'B':

ProcessSelectionB;

break;

:

}


Ternary operator

Ternary operator

  • C++ also has a selection operator – an operator that selects between one of two expression, depending on the input data

  • operators are applied to expressions to produce values of interest:

    (FahrenheitTemp - 32) / 1.8

  • Like switch, the ternary operator is simply a convenience – the role it plays can be performed by if-else...


Ternary operator1

Ternary operator

The following example outputs “Pass” or “Fail”, depending on value of Mark:

cout<< ((Mark>=50)?"Pass":"Fail ");

syntax:

((<condition>)?<expression 1>:<expression 2>)

same as:

if (Mark>=50)

cout << "Pass";

else

cout << "Fail";

ifcondition is True, expression 1 is evaluated; otherwise, expression 2 is evaluated


More on loops

More on Loops

  • We have been using one C++ repetition (loop) statement – while

    while ( <condition> )

    {

    < while statements >

    }

    NbrTimesTold = 0;

    while (NbrTimesTold < NbrTimesToTell)

    {

    cout << “No new taxes!“ << endl;

    NbrTimesTold = NbrTimesTold + 1;

    }


While a review

while – a Review

  • Commonlooping errors are:

    • loops that fail to stop (continue forever)

    • loops that stop one repetition too early

    • loops that perform one repetition too many

    • loops that fail to start

  • Normal while-loop structure is…


While a review1

while – a Review

  • < initialise variables in while-condition >

  • while ( <condition> )

  • {

  • < while statements >

  • < updatevariables in while-condition >

  • }

    • NbrTimesTold = 0;

    • while (NbrTimesTold < NbrTimesToTell)

    • {

      cout << “No new taxes!“ << endl;

      NbrTimesTold = NbrTimesTold + 1;

      }


Activity

Activity

  • What will the following code output?

Number = 5;

while (Number > 0)

{

Sum = Sum + Number ;

Number = Number - 1 ;

}

cout <<“The sum is “<<Sum <<endl;


Activity feedback

Activity Feedback

  • Output depends on initial value of Sum

  • if Sum is zero at start: “The sum is 15”

  • must always initialise a sum to zero!

Number = 5;

while (Number > 0)

{

Sum = Sum + Number ;

Number = Number - 1 ;

}

cout <<“The sum is “<<Sum <<endl;


Activity1

Activity

  • What will the following code output?

Sum = 0 ;

while (Number > 0)

{

Sum = Sum + Number ;

Number = Number - 1;

}

cout <<“The sum is “<<Sum <<endl;


Activity feedback1

Activity Feedback

  • Output depends on initial value of Number

  • must initialise variables in while condition!

Sum = 0 ;

while (Number > 0)

{

Sum = Sum + Number ;

Number = Number - 1;

}

cout <<“The sum is “<<Sum <<endl;


Activity2

Activity

  • What will the following code output?

Sum = 0 ;

Number = 5;

while (Number > 0)

{

Sum = Sum + Number ;

Number++;

}

cout <<“The sum is “<<Sum <<endl;


Activity feedback2

Activity Feedback

  • Loop will never end – an infinite loop

  • This is a logic error! Always check loop conditions carefully.

Sum = 0 ;

Number = 5;

while (Number > 0)

{

Sum = Sum + Number ;

Number++;

}

cout <<“The sum is “<<Sum <<endl;


While vs do while

while vs do-while

  • The while statement tests a condition atthe start of the loop

  • The do-while statement tests a condition atthe endof the loop


While vs do while1

while vs do-while

  • The while statement tests a condition atthe startof the loop

    cout << “Select a direction – N,S,E or W ==> “;

    cin >> Char;

    while ((Char != ‘N’) && (Char != ‘S’) &&

    (Char != ‘E’) && (Char != ‘W’))

    {

    cout << “Invalid direction!” << endl;

    cout << “Select a direction – N,S,E or W ==> “;

    cin >> Char;

    }


Do while loops

do-while loops

  • If a task must be performed at least once, we can perform the test at the end of the loop using do-while

    do

    {

    cout << “Select a direction – N,S,E or W ==> “;

    cin >> Char;

    if ((Char != ‘N’) && (Char != ‘S’) &&

    (Char != ‘E’) && (Char != ‘W’))

    cout << “Invalid direction!” << endl;

    }while ((Char != ‘N’) && (Char != ‘S’) &&

    (Char != ‘E’) && (Char != ‘W’));


Activity3

Activity

  • What are advantages and disadvantages of this design (compared to using while)?

    do

    {

    cout << “Select a direction – N,S,E or W ==> “;

    cin >> Char;

    if ((Char != ‘N’) && (Char != ‘S’) &&

    (Char != ‘E’) && (Char != ‘W’))

    cout << “Invalid direction!” << endl;

    }while ((Char != ‘N’) && (Char != ‘S’) &&

    (Char != ‘E’) && (Char != ‘W’));

    Can you suggest an improvement?


Activity feedback3

Activity Feedback

  • One advantage of do-while is that there is only one copy of prompt and input lines

    cout << “Select a direction – N,S,E or W ==> “;

    cin >> Char;

    while ((Char != ‘N’) && (Char != ‘S’) &&

    (Char != ‘E’) && (Char != ‘W’))

    {

    cout << “Invalid direction!” << endl;

    cout << “Select a direction – N,S,E or W ==> “;

    cin >> Char;

    }


Activity feedback4

Activity Feedback

  • One advantage of do-while is that there is only one copy of prompt and input lines

    do

    {

    cout << “Select a direction – N,S,E or W ==> “;

    cin >> Char;

    if ((Char != ‘N’) && (Char != ‘S’) &&

    (Char != ‘E’) && (Char != ‘W’))

    cout << “Invalid direction!” << endl;

    }while ((Char != ‘N’) && (Char != ‘S’) &&

    (Char != ‘E’) && (Char != ‘W’));


Activity feedback5

Activity Feedback

  • One disadvantage of do-while is that the loop condition appears twice

    do

    {

    cout << “Select a direction – N,S,E or W ==> “;

    cin >> Char;

    if ((Char != ‘N’) && (Char != ‘S’) &&

    (Char != ‘E’) && (Char != ‘W’))

    cout << “Invalid direction!” << endl;

    }while ((Char != ‘N’) && (Char != ‘S’) &&

    (Char != ‘E’) && (Char != ‘W’));


Activity feedback6

Activity Feedback

  • One disadvantage of do-while is that the loop condition appears twice

    cout << “Select a direction – N,S,E or W ==> “;

    cin >> Char;

    while ((Char != ‘N’) && (Char != ‘S’) &&

    (Char != ‘E’) && (Char != ‘W’))

    {

    cout << “Invalid direction!” << endl;

    cout << “Select a direction – N,S,E or W ==> “;

    cin >> Char;

    }


Activity feedback7

Activity Feedback

  • Repetition of complex loop conditions can be avoided using a Boolean variable…

    WaitingForDirection = true;

    do

    {

    cout << “Select a direction – N,S,E or W ==> “;

    cin >> Char;

    if ((Char != ‘N’) && (Char != ‘S’) &&

    (Char != ‘E’) && (Char != ‘W’))

    cout << “Invalid direction!” << endl;

    else

    WaitingForDirection = false;

    }while ( WaitingForDirection );


Activity4

Activity

  • Is the following logic OK?

    • Sum = 0 ;

    • do

    • {

    • cout << “Enter a number (-9 to quit) ==> ";

    • cin >> Number;

    • Sum = Sum + Number;

    • } while (Number != -9);

    • cout << “Sum = “ << Sum;

  • if not, fix it.


Activity feedback8

Activity Feedback

  • The problem with the logic is that it will include –9 in the sum – it should be:

    • Sum = 0 ;

    • do

    • {

    • cout << “Enter a number (-9 to quit) ==> ";

    • cin >> Number;

    • if (Number != -9)

    • Sum = Sum + Number;

    • } while (Number != -9);

    • cout << “Sum = “ << Sum;

note: you will often see

loop conditions repeated

in do-while statements


For vs while

for vs while

cout << “Number of marks in exam ==> “;

cin >> NbrMarks;

cout >> “Number of students ==>“

cin>> NbrStudents;

NbrLoops= 0;

while (NbrLoops < NbrStudents)

{

cout << “Student’s mark ==> “;

cin >> StudentMark;

Percentage = 100 * StudentMark / NbrMarks;

cout << “ Student’s percentage: “;

cout << Percentage;

NbrLoops = NbrLoops +1;

}

notes: initialiseloop control variable


For vs while1

for vs while

cout << “Number of marks in exam ==> “;

cin >> NbrMarks;

cout >> “Number of students ==>“

cin>> NbrStudents;

NbrLoops= 0;

while (NbrLoops < NbrStudents)

{

cout << “Student’s mark ==> “;

cin >> StudentMark;

Percentage = 100 * StudentMark / NbrMarks;

cout << “ Student’s percentage: “;

cout << Percentage;

NbrLoops = NbrLoops +1;

}

notes: loop condition


For vs while2

for vs while

cout << “Number of marks in exam ==> “;

cin >> NbrMarks;

cout >> “Number of students ==>“

cin>> NbrStudents;

NbrLoops= 0;

while (NbrLoops < NbrStudents)

{

cout << “Student’s mark ==> “;

cin >> StudentMark;

Percentage = 100 * StudentMark / NbrMarks;

cout << “ Student’s percentage: “;

cout << Percentage;

NbrLoops++;

}

notes: modify loop control variable

(to avoid looping forever)


For vs while3

for vs while

cout << “Number of marks in exam ==> “;

cin >> NbrMarks;

cout >> “Number of students ==>“

cin>> NbrStudents;

for(NbrLoops = 0; NbrLoops <NbrStudents; NbrLoops++)

{

cout << “Student’s mark ==> “;

cin >> StudentMark;

Percentage = 100 * StudentMark / NbrMarks;

cout << “ Student’s percentage: “;

cout << Percentage;

}

notes: initialiseloop control variable


For vs while4

for vs while

cout << “Number of marks in exam ==> “;

cin >> NbrMarks;

cout >> “Number of students ==>“

cin>> NbrStudents;

for(NbrLoops = 0;NbrLoops <NbrStudents; NbrLoops++)

{

cout << “Student’s mark ==> “;

cin >> StudentMark;

Percentage = 100 * StudentMark / NbrMarks;

cout << “ Student’s percentage: “;

cout << Percentage;

}

notes: loop condition


For vs while5

for vs while

cout << “Number of marks in exam ==> “;

cin >> NbrMarks;

cout >> “Number of students ==>“

cin>> NbrStudents;

for(NbrLoops = 0; NbrLoops <NbrStudents; NbrLoops++)

{

cout << “Student’s mark ==> “;

cin >> StudentMark;

Percentage = 100 * StudentMark / NbrMarks;

cout << “ Student’s percentage: “;

cout << Percentage;

}

notes: modify loop control variable

(to avoid looping forever)


For loop syntax

for Loop Syntax

for( < loop initialisation statement > ;

< loop condition > ;

< loop completion statement > )

{

< for statements >

}

notes: parentheses around forclause


For loop syntax1

for Loop Syntax

for( < loop initialisation statement > ;

< loop condition > ;

< loop completion statement > )

{

< for statements >

}

notes: statement performed once before entering loop for first time


For loop syntax2

for Loop Syntax

for( < loop initialisation statement > ;

< loop condition > ;

< loop completion statement > )

{

< for statements >

}

notes: semi-colons after loop initialisation and loop condition


For loop syntax3

for Loop Syntax

for( < loop initialisation statement > ;

< loop condition > ;

< loop completion statement > )

{

< for statements >

}

notes: condition tested at the start of each loop – including the very first loop


For loop syntax4

for Loop Syntax

for( < loop initialisation statement > ;

< loop condition > ;

< loop completion statement > )

{

< for statements >

}

notes: statement performed at the end of each loop


For loop operation

for Loop Operation

false

loop

initialise

statement

loop

condition

for

true

loop

statements

loop

completion

statement


Activity5

Activity

  • What output is produced by the following code:

for( int Counter = 0; Counter < 5; Counter++ )

{

cout << “Counter = “ << Counter << endl;

}


Activity feedback9

Activity Feedback

  • The output produced by this code is:

Counter = 0

Counter = 1

Counter = 2

Counter = 3

Counter = 4


Loop control variables

Loop Control Variables

  • Usually an integer, but can be a character can be declared within the forclause – instead of...

    int NbrLoops;

    cout << “Number of marks in exam ==> “;

    cin >> NbrMarks;

    cout >> “Number of students ==>“

    cin>> NbrStudents;

    for(NbrLoops = 0; NbrLoops <NbrStudents; NbrLoops++)

    {

    cout << “Student’s mark ==> “;

    cin >> StudentMark;

    Percentage = 100 * StudentMark / NbrMarks;

    cout << “ Student’s percentage: “;

    cout << Percentage;

    }


Loop control variables1

Loop Control Variables

cout << “Number of marks in exam ==> “;

cin >> NbrMarks;

cout >> “Number of students ==>“

cin>> NbrStudents;

for(int NbrLoops = 0; NbrLoops <NbrStudents; NbrLoops++)

{

cout << “Student’s mark ==> “;

cin >> StudentMark;

Percentage = 100 * StudentMark / NbrMarks;

cout << “ Student’s percentage: “;

cout << Percentage;

}


Loop control variables2

Loop Control Variables

int NbrLoops;

cout << “Number of marks in exam ==> “;

cin >> NbrMarks;

cout >> “Number of students ==>“

cin>> NbrStudents;

for(int NbrLoops = 0; NbrLoops <NbrStudents; NbrLoops++)

{

cout << “Student’s mark ==> “;

cin >> StudentMark;

Percentage = 100 * StudentMark / NbrMarks;

cout << “ Student’s percentage: “;

cout << Percentage;

}

notes: if you try to declare the same variable twice, you get a compilation error


Activity6

Activity

  • What output is produced by the following code?

for( int Counter = 0; Counter!=5; Counter++ )

{

cout << “Counter = “ << Counter << endl;

Counter = Counter + 1;

}


Activity feedback10

Activity Feedback

  • The output produced by this code is:

Counter = 0

Counter = 2

Counter = 4

Counter = 6

Counter = 8

:

( until you terminate the program! )


Activity7

Activity

  • Write theforclause of a forloop to produce this output:

  • Counter = 15

  • Counter = 14

  • Counter = 13

  • Counter = 12

  • Counter = 11

  • Counter = 10


Activity feedback11

Activity Feedback

  • Theforclause of a forloop to produce this output is:

  • for( int Counter = 15;

  • Counter>= 10;

  • Counter-- )


Nested loops

Nested Loops

  • We saw that an if-else statement can be embedded inside another if-else statement

  • Likewise, a for statement can be nested inside another for statement

  • In fact, any selection statement (if-else, switch) or repetition statement (while, do-while, for) can be embedded inside another selection or repetition statement

  • With a nested loop, one performs one or more trips around the inner loop for each trip around the outer loop.Here’s an example...


Nested loops1

Nested Loops

for ( int RowNbr = 1; RowNbr <= 5; RowNbr++)

{

cout << endl << “Row “ << RowNbr << “:“;

for ( int ColNbr = 1; ColNbr <= 3; ColNbr++)

{

cout<<" Col " << ColNbr ;

}

}

inner loop


Activity8

Activity

for ( int RowNbr = 1; RowNbr <= 5; RowNbr++)

{

cout << endl << “Row “ << RowNbr << “:“;

for ( int ColNbr = 1; ColNbr <= 3; ColNbr++)

{

cout<<" Col " << ColNbr ;

}

}

activity: what does this code produce as output


Activity feedback12

Activity Feedback

for ( int RowNbr = 1; RowNbr <= 5; RowNbr++)

{

cout << endl << “Row “ << RowNbr << “:“;

for ( int ColNbr = 1; ColNbr <= 3; ColNbr++)

{

cout<<" Col " << ColNbr ;

}

}

feedback: this code produces the following output…

Col 1 Col 2 Col3


Nested loops2

Nested Loops

for ( int RowNbr = 1; RowNbr <= 5; RowNbr++)

{

cout << endl << “Row “ << RowNbr << “:“;

for ( int ColNbr = 1; ColNbr <= 3; ColNbr++)

{

cout<<" Col " << ColNbr ;

}

}

inner loop

outer loop


Nested loops3

Nested Loops

for ( int RowNbr = 1; RowNbr <= 5; RowNbr++)

{

cout << endl << “Row “ << RowNbr << “:“;

for ( int ColNbr = 1; ColNbr <= 3; ColNbr++)

{

cout<<" Col " << ColNbr ;

}

}

note: here, three trips around the inner loop are performed for each trip around the outer loop


Activity9

Activity

for ( int RowNbr = 1; RowNbr <= 5; RowNbr++)

{

cout << endl << “Row “ << RowNbr << “:“;

for ( int ColNbr = 1; ColNbr <= 3; ColNbr++)

{

cout<<" Col " << ColNbr ;

}

}

activity: what is the output produced by this code?


Activity feedback13

Activity Feedback

for ( int RowNbr = 1; RowNbr <= 4; RowNbr++)

{

cout << endl << “Row “ << RowNbr << “:“;

for ( int ColNbr = 1; ColNbr <= 3; ColNbr++)

{

cout<<" Col " << ColNbr ;

}

}

feedback: the output produced by this code is

Row 1: Col 1 Col 2 Col 3

Row 2: Col 1 Col 2 Col 3

Row 3: Col 1 Col 2 Col 3

Row 4: Col 1 Col 2 Col 3


Summary

Summary

  • The switch statements provide a convenient alternative to simple if-else-if statements

  • The ternary operator provides some useful additional flexibility to the power of expressions

  • The task in the “do-while” loop is performed at least once

  • The for loop is useful when the number of required trips around a loop is known before entering the loop

  • Consequently, the for loop is useful when using arrays – the topic of a future class


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