1. 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
' ' Don't do that
that"
"She said
" " She said "hi"
"hi""
"Backslash: Backslash:
"
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2. F2037 PROGRAMMING FUNDAMENTAL WITH C++
1
[newline] n "1n2"
2
[horizontal tab] t "1t2" 12
• 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 below
Step 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()
{
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3. F2037 PROGRAMMING FUNDAMENTAL WITH C++
string name;
cout << "Please enter your name : ";
cin >> name;
cout << "Your name have " <<
name.size() << "
characters.n";
}
Activity 3B
Procedure :
Step 1: Type the programs given below
Step 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 below
Step 2: Compile and run the program. Write the output.
Step 3: Save the program as Lab3C.cpp.
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4. F2037 PROGRAMMING FUNDAMENTAL WITH C++
#include <iostream>
#include <iomanip>
using namespace std;
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 below
Step 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);
}
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5. F2037 PROGRAMMING FUNDAMENTAL WITH C++
else {
cout <<
resetiosflags(ios::left);
}
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 below
Step 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
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6. F2037 PROGRAMMING FUNDAMENTAL WITH C++
Display the following output using function provided in header
file, iomanip.
**********
********
*****
***
*
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)
Check:
c If a = 4, b = 3
b hence c = 5
a
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