Table of Contents

Introduction

In this post, we will see how to display a neat table of values in the C++ program. Displaying a table of data is a very common activity when performing numeric computations.

In C++ we can manipulate the I/O stream using iomanip library.

#include <iomanip>

C++ program

/*************************************** 
*Table of values demo C++ program.
**************************************/ 
#include<iostream>
#include<iomanip>
#include<math.h>

using namespace std;

// Main method 
int main() { 
 double n=1;
 int colWidth=15;
 //table header 
cout << setfill('*') << setw(3*colWidth) << "*" << endl;
cout << setfill(' ') << fixed;
cout << setw(colWidth) << "n" << setw(colWidth) << "log" << setw(colWidth) << 
"square root" << endl; 
cout << setfill('*') << setw(3*colWidth) << "*" << endl; 
cout << setfill(' ') << fixed; 

// create table of data 
while (n < 1000) { 
 cout << setprecision(0) << setw(colWidth) << n << setprecision(4) << 
setw(colWidth)
 << log10(n) << setw(colWidth) << sqrt(n) << endl; 
 if(n < 10) { 
 n++; 
 } 
 else if ( n< 100) {
 n += 10; 
 } else {
 n *= 10;
 } 
} 
cout << setfill('*') &lt;< setw(3*colWidth) << "*" << endl; 
return 0;
}

Program Output

The loop used in the program is a while loop. while loop is a repetitive structure. The while loop is used to execute a group of statements repeatedly in the C++ program until the loop condition is true.

while (n < 1000){
…
}

The loop condition is n < 1000

Functions used

Each row in the table displays three values. n, the logarithm of n to base 10 and the square root of n.
n, log10(n), sqrt(n)

The functions used in the program are math library functions to compute log base 10, square root of the number. To use these function in the program we need to include the header file.

#include<math.h>

setw() sets the field width. setfill() sets the fill character.

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