F2037 PROGRAMMING FUNDAMENTAL WITH C++

LAB 3: INPUT/OUTPUT

Objectives

By the end of this lab, students should be able to : Describe the structure of input-output statement Write a program that use the input and output

statements

Theory/ Topics

In C++, << is called stream insertion operator. Output on standard output device (such as monitor) is

accomplish via the use of cout and operator >>. In C++, >> is called stream extraction operator. Input from the standard input device (such as

keyboard) is accomplished by using cin. To use cin and cout, the program must include header

file iostream. A manipulator is used to format output. endl is the simplest manipulator which cause insertion

point to move to the beginning of next line. In C++, \ is called the escape character while \n is

called newline escape sequence. Common escape sequence is shown in the following

table:

For this Use this Example Output

' \'"Don\'t do that"

Don't do that

" \""She said \"hi\""

She said "hi"

\ \\ "Backslash: \\"Backslash: \

[newline] \n "1\n2"12

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F2037 PROGRAMMING FUNDAMENTAL WITH C++

[horizontal tab] \t "1\t2" 1 2

Manipulators allowed us to format the output in a desired way.

To use manipulator we need to include header file iomanip.

The following table is showing manipulators that is commonly used:

Syntax Purpose

setprecision(n) Set decimal precision 

setfill(c) Setfill character

setw(n) Set field width

Activity 3A

Procedure :

Step 1: Type the programs given belowStep 2: Compile and run the program. Write the output.Step 3: Save the program as lab3A.cpp.

The following program illustrate input name from user and the usage of usage of header file string.h

#include <iostream>#include <string >

using namespace std;

void main() { string name; cout << "Please enter your name : "; cin >> name;

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F2037 PROGRAMMING FUNDAMENTAL WITH C++

cout << "Your name have " << name.size() << " characters.\n"; }

Activity 3B

Procedure :

Step 1: Type the programs given belowStep 2: Compile and run the program. Write the output.Step 3: Save the program as Lab3B.cpp.

// setfill example#include <iostream>#include <iomanip>using namespace std;

int main () { cout << setfill ('x') << setw (10); cout << 77 << endl; return 0; }

Activity 3C

Procedure :

Step 1: Type the programs given belowStep 2: Compile and run the program. Write the output.Step 3: Save the program as Lab3C.cpp.

#include <iostream>#include <iomanip>

using namespace std;

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F2037 PROGRAMMING FUNDAMENTAL WITH C++

int main() { const int max = 12; const int width = 6; for(int row = 1;row <= max;row++) { for(int col = 1;col <= max;col++) { cout << setw(width) << row * col; } cout << endl; } return 0; }

Activity 3D

Procedure :

Step 1: Type the programs given belowStep 2: Compile and run the program. Write the output.Step 3: Save the program as Lab3C.cpp.

#include <iostream>#include <iomanip>

using namespace std;

int main(){

const int max = 12;const int width = 6;for(int row = 1;row <= max;row++) {

if(row % 2) { cout << setiosflags(ios::left);}else {

cout << resetiosflags(ios::left);

}

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F2037 PROGRAMMING FUNDAMENTAL WITH C++

for(int col = 1;col <= max;col++) {

cout << setw(width) << row * col;

}cout << endl;

}return 0;

}

Activity 3D

Procedure :

Step 1: Type the programs given belowStep 2: Compile and run the program. Write the output.Step 3: Save the program as Lab3D..cpp.

#include <iostream>#include <iomanip>

using namespace std;

int main() { double x = 800000.0/81.0; cout << setprecision(2) << x; return 0; }

Exercise 3.1

Display the following output using function provided in header file, iomanip.

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F2037 PROGRAMMING FUNDAMENTAL WITH C++

***************************

Exercise 3.2

Write a program the will receive an input in $US and display the corresponding value in RM. (RM3.52 = $US1).

Exercise 3.3

Write a program that will receive 2 inputs (a and b) and calculate the value of c by using Pythagoras Theorem.

(Hint: Use mathematical library functions)

6

a

bc

Check: If a = 4, b = 3 hence c = 5