C++ Tutorial Index

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C++ Control Statements

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C++ Exception Handling

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Passing by the pointer in C++ Free vs delete() in C++ goto statement in C and C++ C++ program to read string using cin.getline() C++ String Concatenation Heap Sort in C++ Swap numbers in C++ Input Iterators in C++ Fibonacci Series in C++ C ++ Program: Alphabet Triangle and Number Triangle C++ Program: Matrix Multiplication C++ Program to Print Fibonacci Triangle Stack in C++ Maps in C++ Queue in C++ C++ Bitset C++ Algorithms Priority Queue in C++ C++ Multimap C++ Deque Function Pointer in C++ Sizeof() Operators in C++ C++ array of Pointers free() Vs delete in C Timsort Implementation Using C++ CPP Templates C++ Aggregation C++ Enumeration C++ Math Functions C++ Object Class C++ Queue Initialize Vector in C++ Vector in C++ C++ STL Components Function overloading in C++ C++ Maximum Index Problem C++ find missing in the second array C++ Program to find the product array puzzle C++ Program To Find Largest Subarray With 0 Sum C++ Program To Move All Zeros To The End Of The Array C++ Program to find the element that occurs once C++ Program to find the largest number formed from an array Constructor Vs Destructor C++ Namespaces C++ OOPs Concept C++ Static C++ Structs C++ Try-Catch C++ User Defined Exceptions C++ Virtual Destructor C++ vs C# Malloc() and new in C++ Palindrome Number Program in C++ Snake Code in C++ Splitting a string in C++ Structure Vs Class in C++ Virtual Function Vs Pure Virtual Function C++ Bidirectional Iterators C++ Forward Iterators C++ Iterators C++ Output Iterators C++ Range-based For Loop Converting string into integer in C++ LCM Program in C++ Type conversion in C++ Add two numbers using the function in C++ Advantage and disadvantage friend function C++ Armstrong Number Program in C++ ATM machine program in C++ using functions Binary to Decimal in C++ Bit Manipulation in C++ C++ Constructor C++ Dijkstra Algorithm Using the Priority Queue C++ int into String C++ Signal Handling Decimal to Binary in C++ Decimal to Hexadecimal in C++ Decimal to Octal in C++ Factorial Program in C++ Function in C++ Hexadecimal to Decimal in C++ Octal to Decimal in C++ Reverse a Number in C++ Structure Vs Class in C++ C++ Forward Iterators C++ Output Iterators C++ Prime number program Char Array to String in C++ Constructor Overloading in C++ Default arguments in C++ Different Ways to Compare Strings in C++ Dynamic Binding in C++ Program to convert infix to postfix expression in C++ SET Data Structure in C++ Upcasting and Downcasting in C++ Reverse an Array in C++ Fast Input and Output in C++ Delete Operator in C++ Copy elision in C++ C++ Date and Time C++ Bitwise XOR Operator Array of sets in C++ Binary Operator Overloading in C++ Binary Search in C++ Implementing the sets without C++ STL containers Scope Resolution Operator in C++ Smart pointers in C++ Types of polymorphism in C++ Exception Handling in C++ vs Java Const Keyword in C++ Type Casting in C++ Static keyword in C++ vs Java Inheritance in C++ vs Java How to concatenate two strings in C++ Programs to Print Pyramid Patterns in C++ swap() function in C++ Structure of C++ Program Stringstream in C++ and its applications rand() and srand() in C / C++ C++ Ternary Operator C++ Scope of Variables While Loop Examples in C++ Star pattern in C++ using For Loops For Loop Examples in C++ Do-While Loop Examples in C++ Top 5 IDEs for C++ That You Should Try Once Assertions in C/C++ C++ Convert Int to String Continue in C++ While loop Diamond Pattern in C++ using For Loop How to Reverse a String in C++ using Do-While Loop How to Reverse a String in C++ using For Loop How to Reverse a String in C++ using While Loop Infinite loop in C++ Loops in C++ Returning Multiple Values from a Function using Tuple and Pair in C++ wcscpy(), wcslen(), wcscmp() Functions in C++ Auto keyword in C++ C++ 11 vs C++ 14 vs C++ 17 C++ STL (Standard Template Library) Differences Between C Structures and C++ Structures Divide by Zero Exception in C++ Dynamic Constructor in C++ Dynamic Memory Allocation in C++ Find the Size of Array in C/C++ without using sizeof() function Floating Point Operations and Associativity in C, C++ and Java Hello World Program in C++ How to create a table in C++ How to Setup Environment for C++ Programming on Mac Implementation of a Falling Matrix in C++ Message Passing in C++ Pointer to Object in C++ Templates in C++ vs Generics in Java Ways to Copy a Vector in C++ What does Buffer Flush mean in C++ sort() function in C++ Structure Sorting (By Multiple Rules) in C++ Similarities between C++ and Java std::distance in C++

Precision of floating point numbers Using these functions floor(), ceil(), trunc(), round() and setprecision() in C++

Precision of floating point numbers Using these functions floor(), ceil(), trunc(), round() and setprecision() in C++

1/2 decimal equal is 0.555555555555555555555 .... An indefinite number of lengths will require the storage of infinite memory, and we usually have 4 or 8 bytes. Floating point numbers thus only store a certain number of important numbers, and the remainder is missing. The accuracy of a floating-point number describes how often significant digits without loss of data it can show. Cout has a standard precision of 6 when extracting floating point, and serializes everything after.

There are few library and methods given below which are used to produce C++ floating point with precision:

ceil():

The ceil() rounds off of the value given to the nearest integer and more than the amount determined.

Example:

// C++ program to demonstrate working of ceil()
// in C/C++
#include<bits/stdc++.h>
using namespace std;
int main()
{
    double a = 2.411, b = 2.500, c = 2.611;
    cout << ceil(a) << endl;
    cout << ceil(b) << endl;
    cout << ceil(c) << endl;
    double x1 = -4.411, y1 = -4.500, z1 = -4.611;
    cout << ceil(x1) << endl;
    cout << ceil(y1) << endl;
    cout << ceil(z1) << endl;
    return 0;
}

Output:

Precision of floating point numbers Using these functions floor()

floor():

Floor rounds the specific value down to the nearest integer that is less than the specific amount.

Example:

/* C++ program to illustrate floor() function in C++*/
#include<bits/stdc++.h>
using namespace std;
int main()
{
          double x0 =3.411, y0 =3.500, z0 =3.711;
          cout << floor(x0) << endl;
          cout << floor(y0) << endl;
          cout << floor(z0) << endl;
          double i01 =-3.411, j02 =-3.500, k03 =-3.611;
          cout << floor(i01) << endl;
          cout << floor(j02) << endl;
          cout << floor(k03) << endl;
          return 0;
}

Output:

Precision of floating point numbers Using these functions round()

round():

Rounds with numbers provided to the nearest integer.

Example:

// C++ program to demonstrate working of round()
// in C/C++
#include<bits/stdc++.h>
using namespace std;
int main()
{
          double p1 = 4.411, p2 = 4.500, p3 = 4.611;
          cout << round(p1) << endl;
          cout << round(p2) << endl;
          cout << round(p3) << endl;
          double x1 = -4.411, x2 = -4.500, x3 = -4.611;
          cout << round(x1) << endl;
          cout << round(x2) << endl;
          cout << round(x3) << endl;
          return 0;
}

Output:

Precision of floating point numbers Using these functions floor()

trunc(): 

After decimal place, Trunc rounds erase digit numbers.

Example:

// C++ program to demonstrate working of trunc()
// in C/C++
#include<bits/stdc++.h>
using namespace std;
int main()
{
          double y01 = 5.411, y02 = 5.500, y03 = 5.611;
          cout << trunc(y01) << endl;
          cout << trunc(y02) << endl;
          cout << trunc(y03) <<endl;
          double s01 = -5.411, s02 = -5.500, s03 = -5.611;
          cout << trunc(s01) <<endl;
          cout << trunc(s02) <<endl;
          cout << trunc(s03) <<endl;
          return 0;
}

Output:

Precision of floating point numbers Using these functions floor()

setprecision(): 

Especially when combined with 'fixed' set precision provides correct floating-point numbers to decimal numbers provided in setprecision brackets.

Example:

// C++ program to demonstrate working of setprecision()
// in C/C++
#include<bits/stdc++.h>
using namespace std;
int main()
{
          double pi = 4.14159, npi = -4.14159;
          cout << fixed << setprecision(0) << pi <<" "<<npi<<endl;
          cout << fixed << setprecision(1) << pi <<" "<<npi<<endl;
          cout << fixed << setprecision(2) << pi <<" "<<npi<<endl;
          cout << fixed << setprecision(3) << pi <<" "<<npi<<endl;
          cout << fixed << setprecision(4) << pi <<" "<<npi<<endl;
          cout << fixed << setprecision(5) << pi <<" "<<npi<<endl;
          cout << fixed << setprecision(6) << pi <<" "<<npi<<endl;
          cout << fixed << setprecision(7) << pi <<" "<<npi<<endl;
          cout << fixed << setprecision(8) << pi <<" "<<npi<<endl;
          cout << fixed << setprecision(9) << pi <<" "<<npi<<endl;
          cout << fixed << setprecision(10) << pi <<" "<<npi<<endl;
          cout << fixed << setprecision(11) << pi <<" "<<npi<<endl;
          cout << fixed << setprecision(12) << pi <<" "<<npi<<endl;
          cout << fixed << setprecision(13) << pi <<" "<<npi<<endl;
}

Output:

Precision of floating point numbers Using these functions floor()



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